Sealed and pressurized, this refill will help to write underwater, upside down, at any angle from -30 degrees Fahrenheit, -35 degrees Celsius to plus 250 degrees Fahrenheit, 121 degrees Celsius. It is 3 times longer than the average pen and is environmentally friendly. This is the replacement cartridge for Q4 multi-action space pen or any other multi-ink ballpoint pen. It has a length of 9.8 cm and breaks down to 8.7 cm or 6.6 cm.