This is a Peak Design camera holder set. I used it to attach a DSLR or iPhone to the straps of a backpack, but I'm selling it because I no longer use it. It's used and shows some signs of wear, but it works without any problems. The backpack straps were thick, and the original screws wouldn't fit, so I've attached a longer, aftermarket screw to one side. This allows it to be securely fastened even to thick straps.