There are only two sizes of straps. Three sizes of 42mm 44mm 45mm are universal, 38mm 40mm 41mm is also universal.
Yuiyuka Slim Magnetic Strap Compatible with Apple Watch Band 44mm 40mm 45mm 41mm 42mm 38mm 49mm Stainless Steel Milanese Loop Wrist Bands Bracelet
The best Apple Watch Ultra straps of 2023
🏆【2023 Newest Original Design ------ IF Official Award Design】: BRG iwatch magnet band is crafted from stainless steel alloy with magnetic closures,
Original Stainless Steel Milanese Loop Compatible with Apple Watch Band 38mm 40mm 41mm 42mm 44mm 45mm 49mm, Magnetic Clasp Replacement Band for iwatch
QRose Stainless Steel Mesh Loop Magnetic Clasp Bands
DYKEISS 4 Pack Slim Braided Solo Loop Bands Compatible for Apple Watch Band 38mm 42mm 40mm 44mm 41mm 45mm 49mm, Stretch Nylon Elastic Thin Strap for
LEIXIUER Milanese Loop for Apple Watch Band 44mm 40mm 45mm 41mm
Marge Plus Compatible with Apple Watch Band Series Ultra SE 8 7 6 5 4 3 2 1 38mm 40mm 41mm 42mm 44mm 45mm 49mm Women and Men, Stainless Steel Mesh
LEIXIUER Milanese Loop for Apple Watch Band 44mm 40mm 45mm 41mm
【Compatible Model & Size】: CTYBB magnetic clasp stainless steel mesh loop fully compatible with apple watch ultra band 49mm 45mm 44mm 42mm series 9
[2 Pack] Original Milanese Loop Compatible with Apple Watch Band 41mm 40mm 38mm 49mm 45mm 44mm 42mm …See more [2 Pack] Original Milanese Loop
LEIXIUER Ocean Band for Apple Watch Bands Ultra 49mm 45mm 44mm
LELONG Slim Watch Band Compatible with Apple Watch
CTYBB for Apple Watch Band Series Ultra SE 8 7 6 5 4 3 2 1 38mm 40mm 41mm 42mm 44mm 45mm 49mm, Stainless Steel Slim & Thin Mesh Magnetic Clasp Strap