The Omega caliber 8520 is an in-house automatic movement found in smaller ladies and mid-size Omega watches. Self-winding movement with Co-Axial Escapement for greater precision, stability and durability. Free sprung-balance system with silicon balance-spring. Automatic winding in both directions to reduce winding time. Rhodium plated finish with exclusive Geneva waves in arabesque. At the time of this post, Omega has 164 models with the caliber 8520. The image above is an 8250 example from a ladies 31mm Constellation watch. Some other models include:

192 other watches in the library run the Omega 8520.

Omega - 231.10.30.20.02.001 Seamaster Aqua Terra 150M Co-Axial 30 Stainless Steel / Silver / Bracelet

Ref. 231.10.30.20.02.001 · 30 mm

Omega - 231.15.34.20.57.002 Seamaster Aqua Terra 150M Master Co-Axial 34 Stainless Steel / Diamond / Blue MOP / Bracelet

Ref. 231.15.34.20.57.002 · 34 mm

Omega - 232.18.38.20.04.001 Seamaster Planet Ocean 600M Co-Axial 37.5 Stainless Steel / Diamond / White / Alligator

Ref. 232.18.38.20.04.001 · 37.5 mm

Omega - 425.32.34.20.60.001 LadyMatic Co-Axial 34 Stainless Steel / Purple

Ref. 425.32.34.20.60.001 · 34 mm