Black Kaweco Piston Sport Fountain PenThe Kaweco Sport piston filler is available as a starter set for ready to use use with a 32ml ink bottle in royal blue or as a pure writing instrument without additional ink. The Kaweco Sport piston fountain pen is the smallest of its kind due to its sophisticated and compact mechanism in terms of the ratio of pen size to ink filling volume. The transparent ink window allows you to keep an eye on the ink level at all times. If the ink runs out, the