Regular Tight Round Liners are made with high quality 316L surgical stainless steel needles, and high quality medical grade plastics and silicon. Their medical grade silicon is made of a softer less stiff silicon than other cartridge systems for less resistance on your machine, meaning less wear on your machine.  These are designed by artists for artists!  .35mm in diameter / long taper. 20 needle cartridges per box

Addictive Ink Cartridge Needles - Tight Round Liners