AVA E3 Mini PMU Pen (2 Batteries) Brand: Soul Nova Stroke: 3mm Needle Protrusion: 0-4mm Pen Weight: 3.7 oz Pen Length: 5.4 inch Pen Diameter: 0.86 Inch Voltage: 4.5 to 11 Volts Battery Capacity: 700mAh Working Hours: 4h-7h Charging Time: 2-3 hours