The reviews from people that say this product doesn't fit, or doesn't work, are from people that didn't know what they were buying. This is a special adapter that allows a 1/4"-20 female thread to fit onto a 5/8"-11 male thread. In other words, this allows a 1/4"-20 female threaded device to thread onto a 5/8"-11 male threaded device. If the threads are different than what is listed, it will not fit, regardless of the diameter. I needed this adapter to allow my Bosch Laser Level to attach to my Johnson Level Tripod. It threaded on seamlessly without effort or issue. This product is very lightweight and seems like it could break under pressure, but I'm sure that's because you have a tiny 1/4" nub on top of a more robust 5/8" receiver. I certainly wouldn't crank down on it you run the risk of snapping off the 1/4" nub. Otherwise, it worked fantastically.