White Line - Emergency Medical Service Fisher Space Pen can write upside down, sideways, underwater, in extreme cold, and in extreme heat making it possible that this purchase may outlast you. The Space Pen refill utilizes revolutionary technology to make sure it performs in a variety of situations. Specifications: Finish: Black Powder Coat Length: 133 mm (5.25') Diameter: 9.5 mm (.380') Weight: 19 grams Refill: Pressurized 35 PSI Operating Range: -35°C to 121°C Package: Gift Packed