The Seal Tight Cast Cover is designed to keep all types of casts or bandages waterproof in both the shower and bath. This item utilizes a special latex-free diaphragm ring to protect the cast from water getting inside. It is quick, simple and offers excellent protection while allowing complete freedom of movement. This item is reusable and is designed to last 6-8 weeks the typical time period of need for a cast. For length, measure from tip of heel to top of cast, add 1 inch. Also available in a wider size.