Powder-coated brass barrel Pressurized cartridge performs in temperatures from -30F to 250F and underwater to 35 ft. Pocket clip Pressurized ink cartridge performs in temperatures from -30F to 250F and underwater to 35 ft, and at any angle. Proprietary ink and delivery system used exclusively in Rite in the Rain Pens will write without skipping in extremely wet conditions. Permanent ink writes through water, sweat, grease, and mud without clumping or smearing.