11mm Dovetail to 20mm Picatinny/Weaver Low Pro Snap-in Rail Adaptor 4 Slot & 9 Slot for Red Dot Reflex Holographic Sight Laser Scope and Other Optics

Exactly what I needed. Added to my 12ga shotgun with a dovetail to use a red dot that was a picatinny rail. After 50 rounds it still feels super stable. Do note that it mainly tightens from whatever clamp the sight or scope uses so you may need to use tools to keep it locked in rather than by hand

Read the reviews which said this was useless garbage. Rolled the dice figuring it is cheap enough to give it a chance. Guess what? This is USELESS GARBAGE. The tiny little spreader springs somehow overpower the set screws meant to lock the adaptor on. Attempting to tighten said set to screws causes them to immediately strip out. Not sure what application this poorly engineered, even more poorly assembled useless garbage might work for, but it certainly did NOT work for me. Upshot is, I'm only out twelve bucks and some foul language.

Just what you need for mounting red dot sights on 11mm rails.

This piece is perfect exactly what I was looking for I don't know why there is so many negative reviews you just got to use your common sense and it will fit perfect FYI put some Loctite on the small screws and oil the pins and squeeze it together a couple of times and you're good to go

Came with missing grub screw so couldn’t even use the product, it’s designed with the screws on the ends and spring loaded so it won’t even tighten unless use an optic to tighten it to your dovetail. Only upside is the thinness on the mount.

It looks nice, but here are my complaints. You will need to go out and buy a Allen key to fit it and some threadlocker. It does come with either. So your $13 will now be closer to $20 to $25. They could have easily added those to the proct and it would have been 5 stars

The concept of this adapter is great, the material quality is great, but the design is a fail because of one crucial flaw. Although there are horizontal end set screws to hold the adapter in the closed position, they do not any clamping pressure to keep this adapter rail solidly mounted, and it slides forward and backward with a scope mounted. There is too much smooth contact area inside the adapter rail's edges. It must be modified with a vertical set screw to act as a rail stop to prevent that undesired movement. The manufacturer should recall all of these and modify them with a vertical set screw, or else trash them which would be a shame because they are otherwise well built. Of course, you can modify it yourself if you have a drill and tap set and a spare set screw to match the thread size. That would be less than an hour's work for most people. Or else, buy the smaller 1 inch size of these adapters which are properly designed with a vertical set screw. The 1 inch size is sold in as set of two, so you can just use two in series if you want to have a longer length picatinny rail adapter.

Bought to add standard rail to top of Rossi .22 pump. Those have 3/8 groove.Gave me the rail to mount a Fastfire 3 to the synthetic stocked galley gun.The biggest bonus is the very low profile this added. Most 3/8 to Pic rail adapters add 1/2 to 1 inch to mounting height. This only added about 1/4 inch. Fits close enough and small enough to not protrude. Just slightly longer than the mount on a FF3. Fits tight enough that less likely to snag.