Kaweco Perkeo Gel Roller All ClearThe Perkeo Gel Roller features everything you'd expect from Kaweco quality workmanship and the familiar octagonal cap and barrel plus it's reasonably priced. The Perkeo has a comfortable triangular grip and comes with a 0. 7mm Black refill. To refill the pen it takes standard EURO gel refills or the Kaweco EURO gel refill, available in 0. 5mm and 0. 7mm. Writing system: Roller ball gel pen Material: plastic Colour: Teal