Sealed Pressurized Black Ink Cartridge, Fine Point
Refill can break off to fit most 2 & 3 color/size ballpoint pens.
Fits most Fisher Space Pens
Writes underwater, upside down, at any angle, from -30 degrees F (-35 degrees C) to +250 degrees F (121 degrees C), over grease, 3 times longer than the average pen, is environmentally friendly and is unconditionally guaranteed!