Cap activation Space Pen®. Cap activation entire cap slides over the barrel to activate mechanism. The pen has thixotropic ink in a hermetically sealed, pressurized reservoir writes three times longer than an ordinary ballpoint. It has a stainless steel precision socket that prevents leaking yet delivers uniform ink flow. Writes: 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. Our pens are proudly Made in America and unconditionally guaranteed with recyclable parts and packaging staying GREEN! Target Markets: Corporate Gifts; Military; Hunters; Law Enforcement; Artists and Designers; Outdoor Enthusiasts; Search & Rescue.