1---Safe & Reusable: This upper arm shower cover is Waterproof TPU material. Moisture protection And the inner sleeve of Comfortable and breathable fabric which is durable, washable, latex-free and non-slippery. 2---Safe for use: Recommend for patients who accept chemotherapy treatment and antibiotic infusions. Also can use for people who is recovering from injuries, surgeries and skin problems. 3---Using tips: Put on the lining and putting sleeve on, bent your arm and lift edge with finger, then press on sleeve to get air out. And It will form a tight seal which does not allow water in. 4---Easing Wearing: Upper arm shower cover high elastic opening makes it easily pull in a non-painful way. will not stick on arm when shower.It can always keep the inner plaster casts or wound dressings dry and arm circulation normal. 5----3 different sizes: our products are suitable for people weighing 45-110kg and are available in 3 sizes. S: Upper arm circumference: 19-23cm, Lower arm circumference: 16-19cm, Weight: 45-64kg M: Upper arm circumference: 23-28cm, Lower arm circumference: 19-23cm, Weight: 65-79cm L: Upper arm circumference: 28-35cm, Lower arm circumference: 23-28cm, Weight: 80-110kg