Mast Filp Gradient color is customized that with different stroke length options: 2.6mm,2.8mm,3.0mm,3.2mm,3.5mm,3.8mm,4.0mm for a wide variety of procedures, suit for all kinds of tattoo style lining, shading, color packing.The Internal structure of the machine allows artists to keep the Flip Pen bagged while making stroke length adjustments, ensuring uninterrupted and seamless tattooing. The ergonomically design helps to reduce hand fatigue during procedures, use Mast coreless motor that this machine continuous operation, Low noise, Long-lasting stability. For more colors please click?Black, Gray, Red, Blue and Green color. Specifications: Diameter:30mm Machine Length: 112mm Stroke Length: 2.6-4.0mm Seven?adjustable option: 2.6mm,2.8mm,3.0mm,3.2mm,3.5mm,3.8mm,4.0mm Motor: Mast Coreless motor Working Voltage: 5-12V