5.0 out of 5 stars easy to install, mounts low and looks clean - ADE Advanced Optics Adapter/Mounting Plate for Red Dot Sight

Used this to mount a Fastfire III on a Ruger Mark IV. I prefer this to using the Picatinny mount on a rail or other scope base that lies along the top of the receiver since it is far less bulky and mounts the sight lower for a cleaner look.

You do have to remove the factory rear sight but that's not a downside to me since I'll be using the dot exclusively.

Giving this 5 stars for "easy to install", 5 stars for sturdiness but only 3 stars for "value for money". 50 bucks seems way too expensive for a couple of small, easily machined pieces, but it's a very good mount and I figure buy once, cry once.