I bought this on Amazon and have been using it for about three weeks. Having this has lowered the hurdle to taking a bath, so I recommend it. It worked fine for my child, who has thin arms. The following is a copy and paste of the Amazon site content. Sent in simple packaging. YuHaru】 Reusable Cast Cover Waterproof Shower Bandage Cover for Children's Arms - Long Manufacturer: YuHaru 【Safe Bathing】 The shower time is a problem when wearing bandages or casts. With this product's excellent waterproof function, you can take a shower or bath with peace of mind even when wearing bandages or casts. 【Completely Waterproof】 The opening is made of elastic silicone. It fits snugly on the arm and prevents water from entering. 【Safe Materials】 Uses safe medical-grade silicone. Latex-free. Manufactured in a factory that has obtained the quality management system for medical devices ISO13485 & CE/German Industrial Standard Certification DIN CERTCO/Medical Device Quality Management System CMDCAS-ISO/US FDA DRLM/Social Responsibility SA8000 certification. 【Product Size】 (Length x Width): 53 x 39cm. Long for children's arms. L-shaped, it covers up to the upper arm. Suitable for children from preschool to elementary school age.