The Cap-O-Matic line of ballpoint pens utilizes cap activation to extend and retract the point, and each carries a gas pressurized PR style ink refill cartridge, which means that they feature all of the unique capabilities that are synonymous with Fisher products. They will write upside down, at any angle, under water, through grease, in extreme temperatures of minus 30 to plus 250 degrees F, on almost any surface, three times longer than the average pen, and, of course, in the gravity free vacuum of space.