The T1372101135100 runs on a Swiss quartz movement, specifically the ETA F05.115 caliber, powered by a Renata 371 battery. It also includes an end-of-life (EOL) indicator and offers an estimated battery life of up to 68 months. https://saicreationswatches.com/products/t1372101135100-t-classic-prx-analog-unisex-watch