Umbra Flex Adhesive Double Hook Keep your small bath necessities elevated and easy to access with Flex Adhesive Double Hook. This storage hook is made of durable plastic, so it’s easy-to-clean, and you’ll never have to worry about it rusting. Easy to install, Flex Adhesive Double Hook includes non-damaging, waterproof adhesive strips that can be applied on various surfaces such as tiles, dry wall, concrete, etc. (does not work on porous surfaces). Flex Adhesive Double hook is great for slim shower stalls where space and storage is limited. One simple hook can make a big difference by providing access to the items you need in the shower. Made to hang two loofahs or washcloths, or a razor, it can also be used on the reverse side of a smooth glass shower stall to hang larger towels, a bathrobe etc.