Metal detectable cryo pens have been designed to work in wet, greasy, powdery and even sub-zero cold temperatures of -20ºC. Pressurized cryo refill will continue to write until theink has run out. This pen will even write upside down where ordinary ballpoint pens will fail. Retractable housing offers extra protection for the pen refill ensuring that the nib will not become damaged if dropped. Housing is blue with red cap to distinguish from other pens. 50/pack.