Wider and shorter with a little stepboard leading up to it. The hook will be turning all those little poles separating the perches into scratching posts. Either ropey or scratchy surface the cat can sharpen its claws on while it's climbing around.
I'm thinking they should be fairly strong adhesive inserts you can just peel off the back and stick them around the poles. When they're worn, you can peel them off without too much difficulty and peel on a new one.
That should be your hook. My cat would love that so fucking much I'm sure. replaceable scratching posts everywhere you separate perches.
It's money in the bank. Take my cat.
