The ETA 2671 is a compact automatic watch calibre produced by ETA. It was introduced in 1971 and remains in production as of 2019.

Designed for ladies watches and other small applications, the 2671 measures just 7¾ lignes (17.2 mm) in diameter and is 4.8 mm tall. It includes hour, minute, and second hands and a date window. The slightly taller ETA 2678 is similar but includes a day wheel.

Mechanical movement with automatical winding, ball-bearing rotor, bi-directional winding, power reserve 38 hours, date with rapid advance, hacking seconds device.

The movement is used with ladies' watches. It is sold by TAG Heuer as their “Calibre 4”.

• Ball RR2101, RR2701