Features: Titanium with a black DLC finish. Reversible, deep-carry pocket clip. Extra titanium Damascus bolt and spare parts. Description: The Big Idea Design Bolt Action Pen is touted to be the most refill-friendly bolt action pen. Period. To prove it, the list of compatible pen refill cartridges is so long, Big Idea put it on an Excel sheet you can access on their website. Adjust the length of the pen using the twist mechanism and your bolt action pen can now accommodate any size refill! This, coupled with the solid metal construction and satisfying bolt action, makes this the perfect EDC pen! Looking for a pen with more teeth? We carry a wide variety of self-defense Tactical Pens!