Fisher Space Pens are built for more than just outer space. These pens will write in just about any condition and on almost any surface. Underwater or over grease. Extreme temperatures (-30 to 250 F/-35 to 121 C). Upside down or floating in a gravity-free zone. Their sealed and pressurized ink cartridges last three times longer than the average pen with an estimated 100-year shelf life. 

The Backpacker Space Pen can hang upside down forever yet function immediately when needed. This pen has been a fan favorite for years due to its ease of carry. Attach this to your keys, backpack, belt loop, hiking gear, fishing sling, camping equipment and much more.