It's a rail mount that clamps on the receiver but it's not for a red dot, it's intended to attach a shell holder ... holy fuck. I showed this dumb shit to my wife and she said "what the fuck is wrong with people? why are they so dumb?" in reference to the 16 reviews which seem to indicate that at least 16 people have bought this shit.

https://www.amazon.com/Trinity-Remin...29HEHZGZQSTDK6