Heckler & Koch USP Match Trigger Kit is a true drop in kit for USP full size pistols. Fits all full size HK USP 9mm, 40 &. This will fit all of the HK German USP 9mm, 40 &. The Match Trigger Kit will adjust the trigger pull on single action(SA)to about4 lbs. And the double action(DA) pull to roughly7.5 lbs. All the while providing an overall smoother trigger with a better trigger reset. Match hammer spring. Match trigger with over travel stop & tool. Match trigger return spring. Match nickel flat/sear spring. Please note: Although the match kit is designed for the full size USP pistols only. The installation on your USP compact models can be achieved as the trigger will need to be slightly modified in order to be installed in your compact model if you want to use the match trigger in your USP compact models. Or you can use your existing USP compact trigger and not the trigger that comes with the Match kit. This ONLY applies to the USP Compact and NOT the full size. All of the other parts work and install the same way between the full size and compact models.