I used this adaptor on my WE Hi capa 5.1 dragoon. It has a rail, correct width, but for whatever reason they didn't bother putting the slits on it. Many lasers and lights require the slit for the bolt to fit through. so that's the only reason i got this.
This adaptor is nothing amazing or out of the box, it simply does what it's meant to do. The rail is the standard size. The mount is width adjustable to fit standard rails, or rails that are too wide.
My only problem with this, is that it's a quarter inch thick. What i mean is this. My gun is about 2 inches wide at the nose, laser is another 2 inches, so that should be 4 inches wide. With this it's 4 1/4 wide. Believe it or not, that extra 1/4 inch really messes with the fit into a pistol pouch. From a designing point of view, there's no way to fix that, it's an adaptor, so i can't blame this product, but it's stupid that my gun doesn't have notches on the rail to begin with (debating on taking a grinder to that rail).
As far as cosmetically, the adaptor makes it look strange, and not as "cool" but airsoft wars aren't won on cosmetics are they?
Adds to over all width of gun, making it difficult to fit in a pistol pouch.