Fisher Space Pen X-750 Explorer Chrome Finish 4.25 in length closed with Chrome body and rubber grip. Removable cap with pocket clip. Pressurized ink cartridge contains visco-elastic thixotropic permanent type ink with 100 year shelf life. Smoothly polished tungsten carbide ball texturized with diamond dust and cradled in a SS Socket and protective heavy duty beveled rim. Contains a PR4 Black ink Medium Point Refill.