Works with Forerunner 645 & 645 Music, Works with vivoactive 3 & vivomove HR, Fits Wrists from 5-8.5", Adjustable with Stainless Hardware, Silicone Construction. The black Quick Release Watch Band is compatible with the Forerunner 645 645 Music vivoactive 3 and vivomove HR series of smartwatches and activity trackers. With the simple slide of a bar the quick release band can be attached quickly and easily. Replace a broken band or just change it for a new look. This silicone watch band features an adjustable buckle closure with stainless hardware. It's 20mm wide and the adjustable strap can fit wrists that are 5-8.5 in circumference.