ECO Skinpop tattoo cartridge needles are easy to install and fit most pen-style machines. A durable membrane prevents ink backflow. The cartridge features a polycarbonate structure with surgical steel needles inserted into precise tips; it is lightweight yet static. The membrane is designed to minimize vibrations. The shell is made of medical-grade PC material. Individually packaged, sterilized with EO GAS. - Lead-free soldering. - Box of 20 pieces - Sterilized with EO Gas - Thickness: 0.25mm, 0.30mm, 0.35mm - Needles: 1, 3, 5, 7, 9, 11, 14, 18 - Long Taper