Warm Tradition Hot Water Bottle Covers are made using the best 100% cotton flannel material and are proudly crafted in the USA. Each cover fits snuggly around Warm Tradition"s standard size hot water bottle (7 inches wide x 12 inches high) and most other brand"s standard size hot water bottles. Covers help the heat last longer and are a great way of protecting your skin during use. All Warm Tradition hot water bottle covers are easily removable and machine washable. (Cold wash is recommended)