Neoprene cover that slips over your existing mask strap to provide a comfy, tangle-free fit. Velcro keeps the strap from moving around.
I bought two straps, one for my 4yo who loves it at the swimming pool. He can now put his mask back on by himself. Straps have double stitches, strong Velcro. Good material. I think this will last until I retire from diving.