The Black Bay 58 is named after the year in which the first TUDOR divers’ watch waterproof to 200 metres was introduced. Among other aesthetic allusions to this famous historic watch, this model has a 39mm diameter case, in keeping with the characteristic proportions of the 1950s Ref. No m79030n-0001 Description Tudor Black Bay 58 39mm steel case Steel bracelet Case 39mm steel case with polished and satin finish Lugs: 20mm lug width Case thickness: 11.9mm Winding Crown Steel screw-down winding crown, with the TUDOR rose in relief, with circular satin-brushed steel winding crown tube Movement: Manufacture Calibre MT5402 (COSC) Self-winding mechanical movement with bidirectional rotor system Bezel: Unidirectional rotatable bezel in steel with 60-minute graduated disc in matt black anodised aluminium and pink gilded markings and numerals Crystal: Domed sapphire crystal Waterproofness: Waterproof to 200m (660 ft) Guarantee: Five-year transferable guarantee with no registration or periodic maintenance checks required Bracelet Riveted steel bracelet with polished and satin finish, with folding clasp and safety catch Size Guide