41 mm/40 mm/38 mm: compatible with Apple Watch SE strap 40 mm 44 mm, for Apple Watch strap 8 41 mm 45 mm, for Apple Watch strap 7 41 mm 45 mm, for Apple Watch strap 6 40 mm 44 mm, for Apple Watch strap 4 40 mm 44 mm, for Apple Watch strap 3 38 mm 42 mm. mm, for Apple Watch bracelet 2 38 mm 42 mm, for Apple Watch strap 1 38 mm 42 mm.