Good quality, should come with the gun - Ruger 57 Optic Base Adapter Plate

Bought this plate to use for my Ruger 57.

Good quality, installation is easy but need to try out different sizes of Torx wrenches because the manual didn't say.
I have a spare Romeo Zero so I bought this plate to use with that. I first put on the red dot and it won't lid up. When I checked I noticed that as I screw down the 2 screws, the red dot plastic body bent. So the battery on the front doesn't have good contact. It's an issue with the dot, not the plate. So I decided to use the metal shield that sig included with the sight. And the issue is that this plate has 4 metal bumps to locate the red dot. However, the metal shield doesn't have 2 front holes. Tossed in between drilling holes on the metal shield or Dremel off the bumps on the plate. Then I got a friend to sand off the bumps, everything goes together and the dot works great. One star was taken off for the need to modify the plate. The good news is this plate is replaceable.

Another thing I need to add after reading the other review is, the description on OP is NOT CORRECT.
This thing only fits Jpoint, shield, and Sig's dots. Doesn't fit the Vortex Venom. The Vortex model is MPN: 90720. And this one is 90723.

Do not go with what's said on the retailer's website, go with the MPN number. I first find this plate from Ruger, and then came here to find it based on the MPN. My suggestion is to find the correct MPN for your red dot from the manufacturer's website, then use that code to buy. Even if the description is wrong you can still get the right item.