Compact pen converts to a full-size pen and PDA stylus. Carbon fiber and 304 stainless steel components are lightweight, strong and corrosion resistant. Pressurized ink cartridge ensures that Inka Pen writes under water, in extreme temperatures, upside down and at any altitude. Multi-functional design, watertight case and standard-size refill make Inka the one pen for a lifetime! Comes complete with a stainless key ring.