Fisher Space Pen pioneering technology in the Trekker pen means it can hang upside down forever yet function immediately when needed. You can always have a reliable pen available for immediate use. The Trekker space pen with a key chain and carabiner attached to the posi-lock cap allows for easy accessibility. The Trekker space pen comes with a break-away lanyard making it easily attachable to a belt loop, back pack, purse, climbing gear, briefcase or anything else that is within your reach. Functional in every situation and under every condition.