Bell & Ross BR-CAL.321-1

Updated version of the BR-CAL.321 with extended power reserve. The '-1' suffix indicates the inclusion of Sellita's Optimization Barrel upgrade, extending power reserve from 42 to approximately 54 hours. Features ETACHRON regulator with fine tuning device. Used in BR 05 Artline Steel & Gold (limited to 99 pieces) and BR 05 Black Ceramic models. Same caliber number used for different finish variants including black/gold and all-black versions.