Pioneering in technology the Trekker pen can hang upside down forever yet function immediately when needed. Always have a reliable pen available for immediate use. Attach your keys to the Trekker Pen. The Trekker space pen with a key chain attached to the posi-lock cap allows for easy accessibility. The Trekker space pen comes with a carabiner and 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. Contains a Fisher PR4 Pressurized Refill, Medium Point, Black Ink