11mm Dovetail to 21mm Upgraded Build-in Locking Screws Picatinny Rail Low Profile Scope Mount Converter Base 3/8" to 7/8" Converter

This is a quality item that grips my Hatsan Mod 25 pistol's 11mm dovetail rails firmly, and I had no trouble mounting Picatinny optics on the top of it. It has three holding screws which is very appropriate for the air guns it will mostly be mounted on (they have intense recoil shocks). The screws are small Torx head for which the vendor supplies the proper "hex" key.My only recommendation would be to make the screws larger in diameter or of high-grade steel. That's because you may want to use loc-tite / threadlocker on them, and even the blue version of that stuff can hold so tight that you won't be able to get these screws out without snapping them off. Don't ask me how I know this.

Perfect fit

Made of good aircraft aluminum and steel material. Holds firmly on my 11mm pistol railWithout slipping due to recoil. There is a set screw to lock it in place. Very easy to install and comes with a Allen wrench.

Worked very well but the tool that comes with it is too short to crank it down enough. The scope fell off after 10 shots and I had to use a T16 bit to crank it down tighter

Great fit. Great price.

I’m giving this five stars, because it appears to be well made and “fit for purpose.” But I bought it for a Beretta shotgun; and the ventilated rib on that gun—and a half dozen other guns I tried it on—is too narrow to mount this rail on it. Matter of fact, I can’t find any similar rail that *will* fit. Smallest they go is 11mm; my rails are 9mm or less. So, be aware!

works good

Fits perfectly to my 11mm rail, and the triple-screw system means that you’re not losing zero nearly as fast as with a shorter adapter. Stable, though make sure to tighten your screws equally and firmly.You get an overhang for the picatinny rail that is very useful when mounting your sight, and you can bring that sight as far and distant from your eyes as you please - it works great.I think this will part will last about as long as your stock, and given the well machined rail and adapter clasp, consider me a believer. Good price, solid design, and a stable platform for any sight you have in mind.