I just picked up a Full Size USP .40 and I'm shopping around for some good sights. I was on HKparts.net and under the ambi-selector, there's a pic with it installed on a gun and the USP had a burred hammer and these awesome rear sights. From the picture it looks like they're tritium, but I don't know if it's a separate shroud that fits around a rear sight blade? or it's a one piece rear sight. I have been looking everywhere and keep coming up with the same 6 sights or so.. Any and all help is appreciated, thanks in advance!