The Apple Watch Sport Loop band was woven from nylon thread to create a hook-and-loop closure. These bands were available for the 40 mm and 44 mm Apple Watch models, and were offered in sizes to fit 130–200 mm wrists (40 mm) and 145–220 mm wrists (44 mm). The bands also fit older Apple Watch sizes.
This band is primarily off-white, with two different color edges. One edge is yellow and the other is blur. The plastic connectors are off-white, and the plastic closure is yellow.
Apple described the Apple Watch Sport Loop band:
“Soft, breathable, and lightweight, the Sport Loop features a hook-and-loop fastener for quick and easy adjustment. The double-layer nylon weave has dense loops on the skin side that provide soft cushioning while allowing moisture to escape. On the reverse side, the attachment loops are securely anchored for superior durability.”
Source: Apple, Bandbreite