I'm new to this forum and am looking for some recommendations for upgrading the stock sights on my USP fullsize. I like the looks of the XS sights "big dot" for my 48 year old eyes. I often have a hard time picking up that tiny white dot as quickly as I'd like on the stock sights and thought this would be a good option. On the XS site they list a part "# HK-0002S-5- setscrew rear." Does anyone know what the setscrew rear is? Do some USP's come with a setscrew in the rear sight for retention? Mine appears to only be a press fit and there is no setscrew. Any other sights you could recommend would be appreciated.