Cal. 2660 was a compact hand-winding 3-handed movement produced from 1971 through 2004 (or perhaps as late as 2010) by ETA. It was closely related to the automatic ETA 2671 and ETA 2678.
ETA produced a variety of movements in the 2600 family since the 1970s. This includes both automatic and hand-winding variants, 7.75 and 8.75 ligne sizes, and 21,600 A/h and 28,800 A/h versions. In the table below, 8.75 ligne movements are denoted with an asterisk and currently-produced movements in bold.