Nite Ize has developed a product category of writing instruments that are specifically designed for use in extreme environments. The Inka Pen is engineered to write in all conditions - underwater, at any altitude, in temperature extremes and at any angle. It's innovative & patented, multi-function design allows you to use it as a quick-use pen or a full-size fine writing instrument, and the stainless steel split ring allows you to attach it securely wherever you need it. Available in stainless steel, the Inka pen offers exceptional strength, durability and corrosion resistance. It features a replaceable pressurized ink cartridge that gives the Inka Pen it's amazing ability to write in extreme conditions as well as a built-in touch screen stylus.