The pen that truly Goes Anywhere, Writes Everywhere but attaches to everything!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 carrying. Attach this to your keys, backpack, belt loop, hiking gear, fishing sling, camping equipment, and much more. Attach it to your kids backpack for school so next time they sign your signature on a doctors note without you knowing, at least it will look authentic because its not in pencil! Think about it. How many keychains do you see that have a pen attached? Now imagine how many times youve needed a pen when you walked back to your car or truck and had to find one? I think weve made our point. The Backpacker Space Pen by Fisher, Goes Anywhere, Writes Everywhere AND attaches to Everything! The perfect gift for someone who thinks they have everything.The Backpacker is a two-piece pen with a key ring attached to the cap of the pen. Each carries a pressurized PR style ink refill cartridge, which means that they offer all of the unique capabilities that are synonymous with Fisher products: they will write upside down at any angle, under water, through grease, extreme temperatures (-30 to +250 degrees F), on almost any surface, three times longer than the average pen, and of course in the gravity free vacuum of space, and all of our pens are lifetime guaranteed for quality against all manufacturing defects.Specifications:Material:AluminumFinish:Anodized AluminumColor:BlueLength:Open 5.65; Closed 4.09Diameter:.40Cartridge:Fisher PR4, Black Ink, Medium Point; Compatible with any PR cartridgePackaging:Moonscape Gift Box with Astronaut Sleeve