4PCS Wing Sung 3009 Piston Fountain Pen Transparent, Fine Nib, in Blue, Pink,Transparent and Purple, Silver Trim The special durable stainless steel nib delivers a weight balance and consistent ink flow that is crucial in a fine writing instrument. Easy to fill with bottle ink : unscrew the end cap, dip into ink, screw back the end cap, and your done! Ready to write! More ink capacity : The piston filling system allow your to store more ink than other fountain pens. Beautiful and convenient : The transparent body make this pen looks beautiful and energetic. You can also check the amount of ink left when writing. Precision Anti-leaking Rotation Design : operating the piston while ink is in the pen will cause ink to leak out of the pen. You can wist the knob end of the barrel in clockwise to lock it until you hear a "click".