Motor: Custom Mast Coreless Motor. Unique and innovative motor assembly improves the machine service life. Mast Siya's stroke is 3 MM, suitable for PMU,? such as eyeliner, eyebrows, lips, and small tattoos. Super slim wireless tattoo pen, only 24mm. LED screen and 0.1V adjustment. Specifications: Weight: 133 g Diameter: 24 MM Length: 140 MM Stroke: 3.0 MM Working Voltage: 5-12 V Speed: 8V/1000RPM Battery Capacity: 1200 mAh Charging: 2 hours Working: More than 4 hours