Compatible with Gamrin Forerunner 265, Forerunner 255, Garmin Vivoactive 4, Venu 2,Samsung Galaxy Watch 3 45mm/Galaxy Watch 46mm, Gear S3 Frontier/Classic, Fossil Gen 5E 44mm, Gen 5 Carlyle/Julianna/ Garrett, Gen 4 Explorist HR, Amazfit GTR 47mm/ 2/ 2e/ Stratos 3/GTR 3/GTR 3 Pro,Ticwatch Pro 3/ 2021/ 2020/GTX, Huawei Watch 3 Pro, GT 2 46mm/2e /2 Pro/GT3 46MM /GT runner.