The Spike's Tactical Standard Lower Parts Kit supplies the small parts you need to finish an AR-15 lower receiver in 5.56. It includes the complete fire control group and an A2 pistol grip, so the internals and the grip come in one package.
The fire control group is a standard mil-spec single-stage trigger, hammer and disconnector with springs. It is a straightforward choice for a first build or for a rifle where you want a known, service-grade parts set.
Features:
Not included: the takedown and pivot pin set. Order those separately if your lower does not already have them.
Fit check: fits standard mil-spec AR-15 lower receivers. After assembly, function-check the safety and trigger reset with the upper installed and the rifle unloaded before you go live.