The Zero Tolerance 0010EB tactical pen is a covert self-defense tool that make a crucial difference when you need it most. This ZT-worthy tactical pen features a rugged machined body of spiral-fluted 6061-T6 aircraft aluminum. For an extra-secure seal and to help keep moisture out, the pen cap includes an O-ring seal. A built-in glass breaker tip is ready to come to the rescue should it be needed, whether as a tool to shatter a windshield to free a trapped victim or as a defensive tool in case of an unexpected attack. Most of the time, however, a ZT tactical pen is simply a superb writing instrument. Equipped with a Rite in the Rain ink cartridge, it writes in any weather, upside down, and in extreme temperatures. The pressurized cartridge means smooth ink flow every time. When refill time comes, it also fits Parker and Fisher Space Pen cartridges. The 0010EB is manufactured with ZT's characteristic tank-like build, yet fits in your pocket as easily as an ordinary ballpoint pen, so it will always be within easy reach when and if you need it.