This is a shower hook designed to attach to a 30mm slide bar. My shower head seems to be a bit large, and it wouldn't fit in the 22.4mm hook, so I'm selling this one. I only used it once to try placing the shower head on the slide bar, so it's practically new and unused. I bought it on Ama◯on, so if you want to know more details, please check Ama◯on.