The top ring that bolts on is awful. It clicks right through half the threads and eventually starts, about 1/4 inch screwing it in from the bottom. This is probably fine if you're installing on thin stock, but if you're using wood over 1/4" thick. ", I'd find something with better threads. I would return them if shipping didn't cost as much as they cost. So my plan is to just keep them for another project or maybe find a better ring :(