11 Magnum Closed - .35mm diameter, long taper Helios Cartridge Needles are the perfect choice for the professional artist. Helios needles are made with an internal rubber band, not a spring, to give the artist an ultra-smooth feel with just the right tension. Compatible with ALL cartridge system machines and grips 100% EO Gas Sterilized and individually packaged Needles made of 316 medical grade stainless steel Medical grade plastic tips 20 Needles per box