Open, the Bullet measures 5.25 inches, with a closed length of 3.75 inches. Contains PR4 Black Ink, Medium Point Refill. Gift boxed. Operating conditions: writes through water and underwater and in extreme weather conditions. Not affected by dirt, grease or cold water. Listed in the Guinness World Records as the 'most versatile pen'. This pen also works in zero gravity - not that it's likely you will need it in space but it makes a great conversation point!