Functions in extreme conditions. The pressurized ink cartridge writes upside down and through moisture without smearing or washing off. Pressurized ink cartridge performs in temperatures from -30F to 250F, under water (up to 35ft), 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. Writes upside down Ink won't skip Writes through water, sweat, grease & mud Features: Pocket clip Point Size: .9mm Manufactured: U.S.A. Length: 6.75in