For Apple Watch Strap Metal Band iWatch Series 11 10 9 8 7 6 5 4 3 2 1 SE Ultra
Ultra 49mm. For Apple Watch Series 4/5/6/SE 40mm. For Apple Watch Series 4/5/6/SE 44mm. Magnetic connector and loop design makes your strap more flexible to adjust the length. For Apple Watch Series 1/2/3 38mm.