Each pen is individually handcrafted and begins as a single copper rod. I meticulously craft them into the final shape on a manual lathe. I've designed them to be as simple as possible - there are only 6 parts in each pen. Each pen will ship with one of my favorite fine tip gel cartridges installed - the Pentel Energel 0.4mm needle point or the Pilot G2 0.7mm. Two styles of ink refill are available: - Pilot G2 - features a slightly larger opening to accommodate the Pilot G2 tip - Pentel Energel - features a smaller opening that is also compatible with many other refills (Sakura Ballsign Knock, Zebra Sarasa Dry and others) The mechanism is simple and secure: carry confidently in your pocket or purse and never worry about an accidental ink stain. If you'd like a different color or size of ink than the standard black, let me know and I'd love to help you find the right one! Dimensions 8mm x 142.5mm (5/16” x 5.6”) 34 g (1.2 oz) Please note: The raw brushed copper finish will allow a natural patina to immediately develop that is truly unique to you. The clear enamel coating will keep the shine and color of the copper fresh and bright. Over time this coating will wear off which allows the natural patina to develop in patterns that are particularly unique to your personal usage of the pen. How you carry it, fidget with it, and write with it will all affect its development.