S1 Sinn Fliegeruhr 657. Reference 657. Watch measures a beautifully measures 41mm and is made from steel. Automatic movement base ETA which is anti-magnetic up to 80.000 A/M. Sapphire crystal on the front and a closed case back. Waterproof 20ATM or 200 meters. Functions are hours, minutes, sweep seconds and date. Rotating bezel for diving. This watch is fitted with a (small sized) original black rubber strap with steel folding clasp. An extra original different style rubber strap (also sized) is with this set as well as a generic black strap with pin buckle. Naturally this watch is complete with the original box and papers dated March 2012. Please be aware that this watch has been sandblasted and is again in new condition. Rare bird in the pre-own ed market! SOLD