I've had 16" medium crashes on this. 14" thin splashes. Think I once put a 20" ride on it, but the gears on the angle adjustment clamp aren't really up to it, they get loose really quick and need checking constantly.
I don't like the way it bites the chrome of anything you tighten it down onto, but there isn't really a cheaper option or a comparable product without spending a great deal more money.
I used it to mount a splash to the tom arms of the studio kit and it 'ate' the black powder coat. I'm glad it isn't on my kit and I'd feel cheeky mounting it to someone else's expensive kit.
I also don't like the fact the base plate which holds the bottom felt is basically a very thin washer, I can imagine that starting to keyhole easily and falling through the tiller rod. A fatter better grade washer is an easy improvement.
Again, a case of you get what you pay for, this is perfectly suitable for a range of situations, but pretty cheap and cheerful.