Our own design of fin keepers are made to last. Soft but strong polyester webbing, sturdy non-rusting plastic side rings and stitched with UV and weather resistant thread. Fully adjustable so one size fits all and will fit securely, regardless of what fins you are wearing or the thickness of your socks. Overlapping double sided velcro on top with a fluoro yellow tab pull makes them very easy to put on, undo and adjust. Fin keepers are a must to help to keep your fins secure on your foot.