Review on Adjustable MTB Bike Disc Brake Bracket Converter Frame Adapter Mounting Holder - Star-Art 20/31.8mm by Cameron Kennedy

The problem is that the description does not adequately describe the piece. The bracket allows you to use a 180mm rear disc brake. I have 160mm so the caliper sits too high because of this mount. The 20mm or 31.8mm size they offer isn't as important as the fact that this mount is too big for what I need. The description says nothing about what size disc brake this space allows. 140mm/160mm is a common entry-level disc brake size. Most people looking for a solution like this won't rock 180mm or 203mm rotors. I think I'll just buy a 180mm disc and keep this mount. I've looked at several different listings and it seems only one of them that I can find says what size it works with and they're over $20 for it. Just know what you're getting.