UNI‑B — Continuously Adjustable Stroke Rotary Tattoo Machine

The UNI‑B is a direct‑drive rotary pen with a fully continuously adjustable stroke from 2.5mm to 4.5mm — no fixed presets, no gaps. Fine‑tune in 0.1mm increments to match any technique, from soft shading to heavy lining. Powered by a high‑speed AVA metal brush DC motor (10,500 rpm) and a replaceable 18500 battery with upgraded circuit protection, the UNI‑B delivers consistent performance even with reverse battery installation. A built‑in rebound function reduces skin trauma, while the color HD screen keeps voltage, hertz, timing, and battery status clearly visible.

Key Features  

- Continuously Adjustable Stroke (2.5–4.5mm) : No fixed steps. Set the stroke to any value between 2.5mm and 4.5mm (e.g., 2.6mm, 3.7mm, 4.2mm). One machine adapts to every style without swapping components.  

- Timing Function : Starts automatically when powered on. Retains timing data after battery changes. Reset by holding “+” and “–” for 3 seconds.  

- Replaceable 18500 Battery with Circuit Protection : Upgraded protection board safeguards the machine’s circuit even if the battery is installed incorrectly.  

- Color HD Screen with Low Battery Alert : Displays voltage, hertz, timing, and remaining power. When battery runs low, the lightning icon flashes for a clear visual warning.  

- Built‑in Rebound Function : Generates adaptive rebound based on skin condition, helping reduce trauma and overwork during longer sessions.  

- Anti‑Slip Grip : Provides secure handling even with gloved or lubricated hands.  

- High‑Speed Motor (10,500 rpm) : True 10,500 rpm delivers ample power, allowing clean skin entry at lower voltages.  

- Upgraded 10C Power Battery : Extended working time (6–8 hours) for full day sessions without mid‑work swaps.

Specifications  

- Material : Aircraft aluminum  

- Stroke : Continuously adjustable from 2.5mm to 4.5mm (no fixed increments)  

- Motor : AVA metal brush DC motor  

- Motor Speed : 10,500 rpm  

- Timing : Auto‑start on power‑on; retains data after battery change; reset with “+” & “–” (3s)  

- Voltage Adjustment : 0.1V step (tap) / 1V step (hold)  

- Battery : 18500 Li‑ion, replaceable (upgraded 10C power cell)  

- Battery Voltage : 3.7V  

- Power Intake : 5W  

- Needle Protrusion : 0–5mm  

- Charging Input : 5V / 2A  

- Pen Net Weight : 190g (without battery)  

- Pen Size : 128mm × 38mm (grip diameter)  

- Working Hours : 6–8 hours  

- Additional Features : Built‑in rebound function, anti‑slip grip, low battery reminder (flashing lightning icon), color HD screen (color matches battery)