FeaturesThe original smooth writing rollerballWater-based inkWrites for up to 2,200 metresWrites for up to 2,200 metresWallet of 6 black inkThe classic green-barrelled pen invented the affordable rollerball market when launched in 1970. If you were at school in the UK in the 70\'s you almost certainly had one at some point. They have tough caps that stood up to a lot of chewing. They\'ve even still got the little removable colour insert in the top of the clip. Cushioned nib, smooth writing rollerball - 0.8mm tip writes a 0.4mm line. Water-based ink writes up to 2,200 metres. The unique writing sensation produced is a combination of a hard alloy tip, set in a flexible Delrin socket, with fibre-fed ink to enable writing at any angle. Still one of the most distinctive pens on the market, Pentel R50 Rollerball Pens (6pc Set) is a design icon, and one of the most successful pens in the world, with over five million, produced each year.