Samsung galaxy watch用磁気ストラップ,samsung galaxy watch 4/classic/3/active2用磁気ストラップ45mm 41mm 46mm/42mm huawei gt/2/2e 20mm 22 watch band _ - AliExpress Mobile
Amazon.co.jp: Compatible with Samsung Galaxy Watch 4 / Galaxy Wacth 4 Classic / Galaxy Watch 3 41 mm 45 mm, Stainless Steel Magnetic Watch Band for Galaxy Watch 42 mm 46 mm,
Made a rough size comparison between galaxy watch 4 and Apple watch series 7 when doing my shopping, maybe this will help someone else. : r/GalaxyWatch