The AG7 is the original Space Pen is used on all manned NASA space flights including the first moon landing mission in the 1960's. Developed by Dr Fisher exclusively with the issues relating to writing in a zero gravity situation and space flight in mind the original Fisher gas presurised ballpen refill allows you to write upside down or at any angle continuously without the ink stopping flowing. The Fisher Space Pen is a must have item for anyone who writes on the go, Police, Couriers, Tradesmen, anyone who works out and about or even for those doing the crosswords in bed!