This handcrafted 500 Series Tactical Click Pen from Matthew Martin has a quadruple woven carbon fiber body and Tellurium copper tip and grip. The pull grip, milled clip, and clip screw are made out of 6Al4V titanium. The pen uses a German-made click mechanism. A pure delight to behold and use. The 500 Series pen includes a Fisher Space Pen ink cartridge, but also accepts Parker refills (sold separately).