This is rail adapter for compact USP... Someone got in a hurry and ordered the compact instead of the full size. I just paid 62 bucks to get it here. Rather then deal with amazon on return I'd rather pass it to member for 50$. That's 50$ shipped for brand new adapter. This is what is needed to mount your more common weapon lights to HK USP pistols. More info here http://www.hkparts.net/shop/pc/GGG-USP-Compact-Pistol-Flashlight-Adapter-p1106.htm
