Although a broken mask strap is not common, a spare mask strap is a great item to have "just in case". Mask strap is 20.5" long and 0.75" wide. Widest part of the strap is 3", on the back. All of our masks are made using silicone, and all of our mask straps are silicone too. Silicone is not prone to dry-rot nor will it deteriorate over time. However, a broken strap may occasionally happen. We stock all of the replacement straps for the masks we carry, and our straps will fit just about any other brand of mask too.