Comments about Stacks and Stacks Suction Spa Hook:
Attached two to the inside glass of our master bath shower, for my wife's shower cap and scrubber. Attached another two onto the fiberglass shower wall in the pool bath, to let swimsuits dry. Extremely easy to install (suction cup with lever, no tools required) and feel very sturdy. All have stayed pin place without issue (two weeks and counting). Perfect!
Comments about Stacks and Stacks Suction Spa Hook:
I got this hook to hang my bathrobe on the back of my smooth wood door. It stayed up for about five days and then fell off. I think it would stick better on tile or glass but it won't hang anything too heavy. It's a neat idea and would be good for the right use.