Hello Shiner,
the sight does not list the USP compact as a choice. Have you tried patchmyer (sp?) they make pretty much the same slip on and they work great. I have one on my P239 and have used them in the past on other pistols. You should be able to find one, if you cant, call one of the two and see if the have one for another model that works on the USP compact. Note: they are very difficullt to get on at first, which is good.