This is a rare Birks RCAF monopusher. It was issued to the Canadian Air Force in the 1960's and then decommissioned. The sterile case back was put on by the Department of National Defence at that time. Birks has had long standing links to the Canadian Military. Since World War 1 they have produced innumerable badges, medals, memorial Birks Bars and of course Watches. Three of their best known are the Birks Eterna, Birks Challenger, and the RCAF Birks using the Venus 175 movement.The crystal, pusher and crown are new as is the strap. The dial and hands and case are original. It was purchased by the previous owner from the estate of the soldier who owned it. It has been serviced and keeping good time.These are increasingly hard to come by. Not many were made and not many survived.I will ship this insured. Anyone outside of North America or the UK please contact me before bidding