"SEAL-TIGHT Original Cast and Bandage Protector for daily showering, bathing or light aquatic exercise. Durable polyvinyl bag prevents water penetration and lasts 6-8 weeks with daily usage and normal care. Excellent for a situation which requires the protection of a cast or bandage. SEAL-TIGHT also protects skin against water penetration e.g. ulcers. Nonlatex diaphragm stretches over cast or bandage to form watertight seal.Comes in two sizes: Standard (Length 22 inches) and Wide (Length 23 inches).Sizing of Adult Short Arm: Measure from tip of finger to top of cast and add 1 inch."