CMC Triggers AR15/AR10 Receiver Kit with Trigger Single Stage Flat 3-3.5 lb. PullParts included in the receiver parts kit include a bolt catch, bolt catch plunger, bolt catch spring, bolt catch roll pin, mag release, mag release button, mag release spring, buffer retainer spring, safety, buffer retainer, safety detent spring, safety detent, trigger guard, trigger guard roll pin, take down detent springs, take down detents, take down pins, and trigger