Cartridge Needles Sizes: 20 pcs tattoo cartridge needles. Those tattoo needles can be used for lining and shading, which can assist you to complete the entire tattoo work. Compatibility: The needle edges are specially designed to catch more ink and light Grey tubes make you enjoy better needle visibility. The cartridge needles are compatible with most tattoo guns. Safety: Each needle cartridge is individually packed and sealed, much safer and more convenient.Ethylene oxide (EO) gas sterilized; single use only. Anti-backflow: Safety membrane inside cartridges system, that stops ink from passing through to the tube or tattoo machine. Compatible with cartridge grips and machines. Easy to Use: Allows tattoo artists to set up tattoo needles and switch needle configuration very quickly during tattooing process. Low profile housing & better ink flow & shaped on the inside.