Introduction
Before the Yocan UNI, cartridge users faced a recurring frustration: would this new cartridge fit my battery? Different brands used different diameters, and a cartridge that fit one battery might wobble or not fit at all in another. The UNI solved this with a mechanically adjustable holder that grips any cartridge from 6mm to 12mm in diameter.
This simple innovation made the UNI a category-defining product. It launched Yocan's UNI line, which now spans multiple generations and variants, all building on the original's core insight: universal compatibility matters more than almost any other feature for cartridge users.
The Adjustable Holder
The UNI's defining feature is its adjustable cartridge bay. A dial on the bottom of the device moves the holder's walls, tightening or loosening the grip to match your cartridge's diameter. The mechanism works smoothly and holds firm once set—cartridges do not wobble or shift during use.
This design provides several practical benefits:
Universal compatibility: Every 510 cartridge fits. No more guessing whether a new brand or product will work with your battery. If it has a 510 thread, the UNI accepts it.
Secure grip: Unlike friction-fit holders that rely on tight tolerances, the adjustable mechanism actively clamps your cartridge. It stays put in pockets, bags, and during handling.
Cartridge protection: The box mod form factor surrounds your cartridge with the device body, protecting glass from impacts. Only the mouthpiece extends above the housing.
Discretion: With the cartridge concealed inside the body, the UNI looks like a small electronic device rather than an obvious vape. The form factor draws less attention than exposed pen-style setups.
Design and Build
The UNI uses a compact box mod shape that fits comfortably in hand or pocket. Despite the internal cartridge bay, it remains reasonably small—larger than pen batteries but smaller than most box mods. The device feels solid without excessive weight.
Available in multiple colors, the UNI offers options beyond standard black. The finish resists scratches reasonably well, though heavy use will eventually show wear on any device in this price range.
A single button handles power and firing. Five clicks on/off, hold to fire—the standard interface most users already know. The button provides satisfying tactile feedback with clear actuation.
Magnetic Connection
The UNI uses a magnetic adapter rather than threading cartridges directly into the device. A small magnetic ring screws onto your cartridge's 510 thread, then the magnetized cartridge drops into the holder and connects automatically.
This system has tradeoffs:
Pros:
- Quick cartridge swapping without threading
- Reduces wear on cartridge threads
- Clean, gap-free connection
Cons:
- Easy to lose the small magnetic adapter
- Adds a step when using new cartridges
- Some users prefer direct threading
The adapter works well in practice, though keeping track of it requires attention. Yocan includes one adapter with the device; replacements are inexpensive if needed.
Voltage Settings
The UNI offers three voltage presets: low, medium, and high. Triple-clicking cycles through settings, indicated by the LED color (typically green, blue, and red, though this varies by model color).
Preset voltages rather than precise adjustment means less control than variable voltage devices, but the three settings cover most use cases:
- Low: Best for ceramic and wick cartridges, flavor-focused hits
- Medium: Balanced setting suitable for most cartridges
- High: Maximum vapor production, better for thicker oils
Most users find one of the three settings works well for their preferred cartridges. Those requiring precise voltage control should look at the UNI Pro or newer UNI variants.
Battery and Charging
The 650mAh battery provides moderate capacity—enough for a day of light to medium use, but heavy users may need to charge mid-day. The compact size necessitates this tradeoff; larger batteries would require a larger device.
Charging uses Micro-USB, which feels dated compared to USB-C but remains functional. A full charge takes approximately 1-1.5 hours depending on the charger. The LED indicates charging status and turns off when complete.
Pass-through charging allows use while connected to power, useful when the battery runs low unexpectedly.
Performance
The UNI performs reliably within its design parameters. Cartridges heat consistently, vapor production matches voltage settings appropriately, and the device fires without delay or hesitation.
Heat-up is nearly instant thanks to the efficient power delivery and low-resistance cartridge coils. Draw-activated firing is not available—you must hold the button while inhaling—but button activation provides consistent results.
The enclosed cartridge design does mean slightly restricted airflow compared to exposed setups. Most users do not notice or adjust quickly, but those accustomed to very airy draws may need to adapt.
Who Should Buy the Yocan UNI
Multi-cartridge users: If you rotate between different brands and products, the adjustable holder eliminates compatibility concerns. Every cartridge works.
Discretion-focused users: The concealed cartridge design draws less attention than exposed pen batteries. In settings where subtlety matters, the UNI helps.
Budget buyers: Priced around $20-25, the UNI delivers quality construction and reliable performance without premium cost. It's an excellent entry point to box mod style batteries.
Gift buyers: The universal compatibility makes the UNI a safe gift choice—recipients can use it with whatever cartridges they prefer.
UNI vs Later Models
Yocan has expanded the UNI line significantly since the original. The UNI Pro adds variable voltage control with an OLED display. The UNI S offers a smaller form factor. The UNI 3 brings USB-C charging and updated features.
The original UNI remains relevant for users who want the core adjustable holder functionality without paying for features they may not need. If preset voltages suit your use and you are comfortable with Micro-USB charging, the original offers the best value in the lineup.
Final Verdict
The Yocan UNI earned its reputation by solving a genuine problem. The adjustable cartridge holder remains the device's defining feature, providing compatibility peace of mind that generic batteries cannot match.
At its price point, the UNI delivers excellent value. The box mod form factor protects cartridges and adds discretion, the magnetic connection simplifies swapping, and three voltage presets cover common use cases. The smaller battery and Micro-USB charging are reasonable compromises for the size and price.
For users prioritizing compatibility and value over advanced features, the original UNI remains a smart choice even with newer options available. It does what it does well, and it does it for less than competitors.
Related: Yocan UNI 3 Review | Yocan UNI Pro 2 Review