The TWSBI Swipe Fountain Pen a remarkable addition to the world of entry-level fountain pens. The Swipe includes three filling systems - cartridges, a traditional piston converter, and a spring-loaded piston converter. All three can hold nearly 1.5 ml of ink, almost as much as a TWSBI ECO – so you don't need to sacrifice capacity for convenience. The Swipe is also compatible with the standard international cartridges and converters, so you'll be able to customize the pen to your writing needs without difficulty.