Bands for 38mm, 40mm and 41mm conditions are compatible with one another, and bands for 42mm, 44mm and 45mm circumstances are suitable with each other. You can find 2 buttons to release the two sides from the watch band. These buttons can be found about the back again on the https://allhealthmarket.com/product/aeahmarket/appleband/silicone-strap-for-apple-watch/apple-watch-strap-double-buckle-band-for-series-1-9-38-49mm-ultra-2-silicone-sport-strap/