Write in the rain, in frigid temperatures (-50 F), in snow storms or in the boiling heat (+400 F) with these Rite in the Rain All Weather Pens in Black Metal, featuring a fine tip and black ink. Permanent ink is pressurized and similar to rubber cement. These pens were originally developed for astronauts, but now Letter Carriers can use that same technology on their postal routes to fill out any type of form. All Weather Pens not only write in any weather, but also over grease, fingerprints, and photos.