Sport Silicone Watch Band Strap For Apple Watch All Series 

Color: 40+ colors

Premium Material - Made of specially high-performance silicone, extremely strong and durable,yet exceptionally soft, so it can be stretched easily.

The smooth and dense material elegantly wraps around the wrist for a comfortable feel on the skin.
Soft, comfortable, durable, sweat-resistant and waterproof, and will not fade.

Which Band Fits My Watch?
Same Size: (38mm/40mm/41mm)
Same Size: (42mm/44mm/45mm/46mm/49mm)
The mm difference is in the display rather than the watch.
That means that the Watch band that fits a 38 mm will also fit the 40 mm and 41 mm.
Likewise, a band that fits a 42 mm will fit the 44 mm, 45 mm and 49mm.