The Geissele Super Dynamic-Combat (SD-C) Trigger featuring an exclusive flat trigger bow, is a rugged, non-adjustable combat trigger with a sear design that provides a wide margin of safety against unintentional discharges yet still gives the operator a sharp, repeatable trigger release. The SD-C is a flat bow variant of the Super Semi-Automatic (SSAA(R)) trigger. Please note, Geissele triggers are designed for mil-spec AR15/M4 carbine rifles. Geissele AR15 triggers are not compatible with the Sig MPX/MCX weapons or Pistol Caliber Carbine AR15/M4 variants. SPECS Type: 2 Stage 1st Stage Weight Range: 2.75 - 3.0 lbs. 2nd Stage Weight Range: 1.5 - 1.75 lbs Mfg: Geissele Automatics SPECS: Steel, black finish. Fits semi-automatic AR-15/M16 receivers with .154" diameter hammer and trigger pin holes. May be installed in AR-style .308 rifles that accept AR-15 triggers. Does not fit HK416 weapons with firing pin safety. Kit includes trigger andhammer assemblies, springs, ha