Pentel N50 Permanent Marker Bullet Tip 2.2mm Line Black (Pack 12) - N50-APentel Black N50 is a robust everyday permanent marker. This Robust permanent marker will write on almost any surface including metal, wood, glass, card and plastic. It has a metal barrel, perfect for long lasting in more harsh working environments! No wonder theyre the number one choice for industry and commerce. The ink is fast drying yet rich in colour. Ink flow is controlled by a valve mechanism to allow a precise application.