Overview Our Apple Watch Ultra Strap is a webbing-leather hybrid strap made with 20mm herringbone nylon webbing for adjustablilty and Newbury leather for a seamless connection between the webbing, buckle, and Apple Watch. The hardware used is Fidlock Hook 20 Flat magnetic buckle for easy attachment and detachment. Strap is compatible with the Apple Watch Ultra only. Disclaimer 1: Fidlock magnetic buckle can potentially affect the functionality of the Compass app on the Apple Watch. Specs Strap Type: 20mm Herringbone Nylon Webbing Newbury Crazy Horse Leather Lug Size: 49mm Hardware Type: Fidlock Hook 20 Flat Buckle   Sizing Measure your wrist circumference (no ease). Standard: 6" - 7.25" Extended: 7.25" - 8.5"