Panthere Mini, Tank Solo Small, Tank Americaine Small (Add your watch to the comments below…)
The Cartier caliber 157 is a 2-hand Swiss made quartz movement with 4 jewels. This example was found in a vintage ladies Must de Cartier Tank (5057001) with a Vermeil case.
Cartier 157 VS 057:
This movement is also similar to the Cartier caliber 057 seen here, the only difference is that the 057 is oval and this caliber 157 is a round shape.
Cartier X Ebel:
You may also see this quartz movement listed as an Ebel 157. This is because Ebel and Cartier were part of a joint venture known as Compagnie Ebel Cartier (CEC), based in La Chaux-de-Fonds. Since 1972, Ebel had been producing watches for Cartier until the two companies formed CEC in 1992. Despite the high quality finishing compared to other quartz, they were produced with cost efficiency in mind and not as High Accuracy Quartz (HAQ) calibers.