Twsbi GO Smoke nib M - Fountain PenTwsbi GO: A new challenge in the world of fountain pen with a pen with special charging system that contributes to an affordable price, easy handling and high writing quality. Hood and handle made of transparent resin, semi transparent body colour: smoke Spring Loaded Piston Filling Refill System To recharge, simply un the pen, insert the pen into the ink and the nib moves the plunger that fills the fountain pen. Steel nib M (medium)