Omega Speedmaster ST145.022

Omega, Speedmaster, ref. ST145.022, steel chronograph wristwatch, 1970s Movement:

Omega Speedmaster, ref. ST145.022, steel chronograph wristwatch, 1970s. Movement: cal. 861, mechanical, 17 jewels. Case: 42 mm diameter. Complications: two-register chronograph with central seconds, tachymeter scale, and subdial for seconds. Signatures: dial, movement, case, and bracelet.