Description Cal. 1137, quartz movement, circular white dial with subdials for chronograph, case no. 2486477/3731, movement no. 2728491, to an aftermarket strap with steel IWC clasp, 25 jewels, movement currently functioning but start/stop functioning is not functioning well, with guarantee booklet and box, 36mm. diam, model: Portofino. Weight / Size / Quality Gross weight 39 grams., A gentlemen's steel wristwatch with chronograph, IWC