🕵️ What Is a Penjamin Cart Pen? How It Works, Specs & Honest Review (2026)

Every week across Reddit’s r/oilpen and r/trees, thousands of users ask the same question: “What is a Penjamin and is it actually worth it?” The device went viral in 2023 and has stayed in the top search results ever since — because it solves a real problem that no standard 510 battery addresses: how to carry a vape cartridge somewhere completely unremarkable.

The Penjamin is not a gimmick. It is a stealth vaping device that is more than just a novelty — it is a solid vape device at $34, an affordable and innovative option for users looking for a 510 battery disguised as a pen that blends into everyday life. This guide explains exactly what it is, how it works, what its real specs are, where it falls short, and how it compares to alternatives — including AOVAPE’s own lineup of discreet 510 thread batteries.

For broader context on the discreet battery category, readers can also browse AOVAPE’s Law concealed battery, the full 510 battery collection, and related guides on the AOVAPE blog.

🖊️ 1. What Is a Penjamin? The Concept Explained

The Penjamin Cart Pen is a dual-function device manufactured by Smyle Labs that operates simultaneously as a standard ballpoint writing pen and a 510-thread oil cartridge battery. From the outside, it is indistinguishable from a premium ballpoint pen. Inside, it houses a rechargeable lithium-ion battery, a 510-thread cartridge mount, and a three-level voltage control system.

The name is derived from Benjamin Franklin, whose face was printed on the pen’s original packaging. The device aims to foster discreet vaping — it comes with a 510 battery and a cartridge compartment compatible with most 0.5g and 1g cartridges.

The core innovation is physical concealment at Level 3 — the highest stealth tier in the 510 battery category:

• 🖊️ External appearance — a ballpoint pen with a soft-finish barrel and standard pen dimensions
• ✍️ Writing function — a real ink cartridge and retractable writing tip (twist the base counterclockwise to deploy)
• 🫙 Concealed cartridge — the cannabis oil cart sits fully inside the pen barrel, invisible from all external angles
• 💨 Mouthpiece — the top cap of the pen; remove it to expose the cartridge chamber and inhale
• 🔋 Power system — integrated rechargeable battery with 3-preset voltage and preheat mode

📌 Unlike standard discreet 510 batteries that merely conceal the cartridge inside a vape-shaped housing, the Penjamin goes one step further: it functions as an entirely different object category. To someone unfamiliar with the device, there is no visible indication that it is a vaping device at all — even at close range.

⚙️ 2. Full Specifications

Understanding the hardware specs is essential for deciding whether the Penjamin fits your actual use case. Here is the complete specification breakdown based on Smyle Labs’ official product documentation and independent reviewer testing:

📌 One significant hardware limitation worth flagging immediately: the Penjamin uses Micro-USB charging, not USB-C. In 2026, this is a clear downside — Micro-USB cables are becoming less common in everyday carry, and the connector is less durable than USB-C (rated for approximately 5,000 insertion cycles vs USB-C’s 10,000+). This is the most-cited complaint in community reviews.

🔧 3. How the Penjamin Works: Step-by-Step

The dual-function design requires understanding two separate operational modes. Here is exactly how each works:

✍️ 3.1 Writing Mode

1. Hold the pen with the top cap (mouthpiece) pointing up
2. Twist the bottom section of the barrel counterclockwise
3. The writing tip deploys from the bottom of the pen
4. Write normally — real ballpoint ink, standard pen pressure
5. Twist clockwise to retract the tip when done

💨 3.2 Vaping Mode

1. Load cartridge: Remove the top cap to expose the 510-thread chamber. Screw in any standard 510-thread 0.5g or 1g cartridge — snug, not overtightened
2. Power on: 5 rapid button clicks to power on the device
3. Set voltage: 3 button clicks cycles through the three voltage presets (2.4V → 3.2V → 4.0V)
4. Preheat (recommended): 2 button clicks activates the preheat cycle — especially important for thick or cold oil
5. Inhale: Hold button and draw slowly through the exposed cartridge mouthpiece
6. Power off: 5 rapid clicks to lock device and prevent accidental firing
7. Conceal: Replace the top cap to fully hide the cartridge

💡 The top cap does double duty: it conceals the cartridge completely when the device is in “pen mode” and protects the oil from UV light exposure between sessions. UV light degrades cannabinoids and terpenes over time — enclosed storage is an underappreciated benefit of the Penjamin’s design beyond stealth alone.

🌡️ 4. Voltage Guide for the Penjamin

The Penjamin’s 3 voltage presets cover the practical range for most oil cartridge types. Matching voltage to your specific oil prevents the two most common problems: burnt taste (voltage too high) and weak vapor (voltage too low).

💡 Community consensus from r/oilpen: start on Low (2.4V) for any new cartridge and work up. The 4.0V High setting is too hot for most live resin and full-spectrum oils — it will burn off terpenes and produce a harsh taste. Reserve the High setting for genuinely thick distillate that does not produce sufficient vapor at Mid.

📌 For users with premium live rosin or solventless carts, even 2.4V may be slightly warm. The Penjamin’s 3-preset system does not go below 2.4V — this is its main limitation compared to premium variable-voltage batteries like AOVAPE’s Vertex, which adjusts in 0.1V increments down to 1.6V.

✅ 5. Honest Pros and Cons

Based on analysis of dozens of verified user reviews, community threads, and independent hardware testing:

🔍 6. Who the Penjamin Is Actually For

The Penjamin solves a specific problem exceptionally well. It does not try to be the best-performing 510 battery — it tries to be the most invisible one. Understanding this distinction clarifies exactly who should buy it.

✅ The Penjamin is the right choice if:

• 🏢 You work in an office and want to vape during breaks without drawing attention
• ✈️ You travel frequently and want a device that passes visual inspection without questions
• 👨‍👩‍👧 You live with family members who do not know you vape and want to keep it that way
• 📚 You are in educational or professional environments where visible vaping is not appropriate
• 💰 You want legitimate Level 3 stealth for under $35

❌ The Penjamin is NOT the right choice if:

• 🌿 You use premium live rosin or solventless carts that need sub-2.4V
• 🔋 You are a heavy daily user who drains batteries fast — undisclosed battery capacity is a risk
• 🔌 You have standardized on USB-C for all your devices and do not want a separate Micro-USB cable
• 🎛️ You want fine-increment voltage control across the full 1.6V–4.2V range for multiple oil types
• 🏠 You primarily vape at home where discretion is not a priority — a standard battery is better value

🆚 7. Penjamin vs. Other Discreet 510 Batteries

The Penjamin is the most recognized name in pen-disguise 510 batteries, but it is not the only option in the discreet category. Here is how it compares to the main alternatives:

📌 The Penjamin’s main competitive advantage is unique: no other device at this price point achieves Level 3 concealment with a fully functional writing pen disguise. Its main disadvantage versus 2026 alternatives is Micro-USB charging. For users who prioritize voltage precision over maximum stealth, AOVAPE’s Vertex or Law offer USB-C charging and more flexible voltage control in a discreet concealed body.

🛡️ 8. Safety and Build Quality

For a $34 device, the Penjamin’s safety feature set is adequate but not comprehensive. Here is what it includes and what it lacks:

• ✅ 5-click power lock — prevents accidental firing in pockets or bags
• ✅ Preheat mode — low-voltage warm-up protects the coil from cold-start stress
• ✅ 3-voltage preset system — limits maximum heat delivered to the cartridge
• ⚠️ No disclosed auto-shutoff timer — the draw duration cutoff is not publicly specified by Smyle Labs
• ⚠️ No battery capacity specification — mAh rating is not disclosed, making battery life assessment impossible before purchase

Build quality is consistently described as premium for the price point across independent reviews. The Smyle Penjamin Cart Pen is made from high-quality materials and has a patented design, boasting an integrated rechargeable battery, included charging cable, 3 adjustable temperature settings, and a preheat function.

🛒 9. Where to Buy and What to Expect

The Penjamin Cart Pen retails for $34–$35 across authorized resellers and is available through:

• 🌐 Smyle Labs official site (smylelabs.com) — most reliable for authenticity and warranty
• 🏪 Independent vape retailers — VGEAR, Discreet Smoker, Vapeguy, and similar specialist retailers
• 💊 Select dispensaries — some cannabis dispensaries carry it alongside cartridges

What is included in the box:

• ✅ Penjamin Cart Pen (battery + writing pen body)
• ✅ Micro-USB charging cable
• ✅ 0.5g cartridge adapter
• ❌ Cartridge NOT included — purchase separately

If you are exploring alternatives with USB-C charging and concealed cart designs, browse AOVAPE’s full 510 thread battery collection for options across all concealment levels, price tiers, and voltage control systems. For wholesale or OEM buyers building a private-label discreet battery line, AOVAPE’s OEM/ODM program covers full custom design with MOQ-flexible production.

❓ FAQ: What Is a Penjamin?

What is a Penjamin cart pen?

A Penjamin cart pen is a 510-thread vape battery disguised as a fully functional ballpoint pen, made by Smyle Labs. It conceals an oil cartridge inside the pen barrel, writes with real ink via a retractable writing tip, and vapes through the top of the pen. It retails for approximately $34–$35 and works with all standard 0.5g and 1g 510-thread cartridges.

How do you use a Penjamin pen?

To vape: remove the top cap, screw in a 510-thread cartridge, press the button 5 times to power on, press 3 times to set voltage, press 2 times to preheat, then hold the button and inhale. To write: twist the bottom of the barrel counterclockwise to deploy the real ballpoint writing tip.

What voltage does the Penjamin use?

The Penjamin has 3 preset voltage settings: 2.4V (Low), 3.2V (Mid), and 4.0V (High). For most standard distillate cartridges, 3.2V is the everyday sweet spot. For live resin or high-terpene oils, use 2.4V. Reserve 4.0V only for thick, high-viscosity distillate.

Does the Penjamin actually write?

Yes. The Penjamin contains a real ink cartridge and a retractable ballpoint writing tip. Twist the bottom of the barrel counterclockwise and the writing tip deploys. It writes like a standard ballpoint pen. Replacement ink cartridges can be sourced from standard pen supply retailers.

What cartridges are compatible with the Penjamin?

The Penjamin is compatible with all standard 510-thread cartridges in 0.5g and 1g sizes. A 0.5g adapter is included in the box. It is not compatible with proprietary pod systems (Pax Era, Bloom, etc.) that use non-510 connections.

What is the difference between a Penjamin and a regular 510 battery?

A standard 510 battery is a vape-shaped device — its function is visually obvious. A Penjamin disguises that same function inside a fully operational ballpoint pen. The hardware performance is comparable (3 voltage presets, preheat mode, 510 threading), but the Penjamin’s form factor is classified as Level 3 stealth — it does not look like a vape device at all.

Is the Penjamin worth buying in 2026?

Yes, for users who prioritize maximum discretion in office, travel, or social environments. Its $34 price point delivers genuine Level 3 stealth performance. The main caveat: it uses Micro-USB charging rather than USB-C. If USB-C compatibility is essential, AOVAPE’s Law battery offers comparable discretion with modern charging.

Where can I buy a Penjamin?

The Penjamin Cart Pen is available through Smyle Labs’ official website (smylelabs.com), authorized vape retailers including VGEAR and Discreet Smoker, and select cannabis dispensaries. Retail price is $34–$35. Always purchase from authorized resellers to ensure authenticity and warranty coverage.

What are the best alternatives to the Penjamin?

The Smyle Car Key 510 (similar price, USB-C charging, keychain disguise) is the closest alternative for Level 3 stealth. For Level 1–2 stealth with better voltage control and USB-C, AOVAPE’s Law and Vertex batteries are strong alternatives. For maximum voltage precision, the Cartisan EVO (~$60) offers 0.1V increments from 1.8V to 4.2V.

📌 Final Thoughts

The Penjamin Cart Pen earns its reputation by doing one thing exceptionally well: achieving Level 3 stealth — the highest concealment tier in the 510 battery market — at an accessible $34–$35 price point. It is not the most technically advanced battery, and its Micro-USB charging is a clear limitation in 2026. But for the specific problem it solves — carrying a cartridge battery somewhere completely unremarkable — nothing in its price range matches it.

For users who need discreet carry without the pen-disguise specifically, AOVAPE’s lineup of concealed 510 batteries offers USB-C charging, variable voltage control, and Level 1–2 stealth across multiple form factors.

👉 Browse AOVAPE’s full discreet 510 battery collection →

👉 View the AOVAPE Law concealed battery →

📚 References

• Penjamin retail price: $34–$35 as of 2026 (Smyle Labs official site; VGEAR reseller pricing, 2026)
• Penjamin voltage presets: 2.4V / 3.2V / 4.0V — confirmed via Smyle Labs official product documentation
• 510 thread standard: 10 threads at 0.5mm pitch — universal industry standard adopted from approximately 2009–2012
• USB-C connector durability: rated for 10,000+ insertion cycles vs Micro-USB’s approximately 5,000 cycles (USB Implementers Forum specification data)
• Terpene degradation threshold: aromatic terpene degradation accelerates above equivalent of approximately 2.8–3.0V on standard 1.5 ohm ceramic coils (Steep Hill Labs cannabis terpene data; community consensus r/oilpen, 2025–2026)
• UV light cannabis oil degradation: cannabinoids and terpenes degrade measurably under UV exposure — enclosed storage extends oil quality (SC Labs cannabis stability testing data)
• Level 3 stealth category: object-disguise 510 batteries that replicate non-vaping objects in full functional detail — terminology standardized across vape hardware review communities (vapeguy.com; discreetsmoker.com, 2025–2026)
• Community verdict on Penjamin: consistently rated as “more than a novelty — a solid vape device” across independent reviews (vapeguy.com, discreetsmoker.com, vapingland.com, 2025–2026)