Nylon Apple Watch straps are light and breathable. They're also comfortable in the middle of summer and you feel like you're melting. These nylon straps are specially made for the Apple Watch and fit well with the watch case. When choosing a nylon Apple Watch strap, make sure you choose the right size for your Apple Watch. The Apple Watch 38, 40, 41, and 42mm straps fit on each of these sizes. The Apple Watch 44, 45, 46, and 49mm straps fit on each of those sizes.