ETA SA 251-264

ETA 251-264 is a Swiss quartz chronograph movement measuring 30mm in diameter and 5mm thick with 27 jewels. It includes a small jumping seconds at 6 o'clock, a date window, and a time-zone mechanism; the date advances through hour-hand jumps rather than a conventional quickset, which also facilitates setting the second time zone. The movement was available in HE and IE variants, offering either a 1/10th second or 12-hour counter. It used a Renata 394 battery with a theoretical life of 72 months. Production is discontinued.