The complete drop-in kit comes with a cnc machined disconnecter, target hammer, hammer bushing, target sear, target trigger with plunger and spring. It also comes with pretravel and overtravel adjustments. The Accurizing Kit for the Ruger MK IV will provide a crisp, clean 2.5lb trigger pull. This kit will eliminate the magazine disconnect. FeaturesHammer and sear are wire EDM Cut from A2 Tool SteelIncludes all WrenchesIncludes medium strength loctiteTrigger made from anodized aluminum