4Pk Waterproof Half Leg Cast Cover for Shower, Boot Guard, Foot Plaster and Bandage Protector Sock for Showering, One Size Fits All, Lightweight, Comfortable, Reusable, Easy to Use, Secure Seal. Comfortable & Lightweight: This cast cover fits snugly over your plaster cast waterproof cover leg, providing comfort without irritation, perfect for daily showers or baths.
eBay