This is a Apex Tactical Specialties Kit, model 100-054.
Designed to work in any Smith & Wesson M&P model pistol in all centerfire calibers" the patented Apex Flat-Faced Forward Set Sear & Trigger Kit reduces trigger pre-travel and over-travel to deliver an unparalleled trigger performance as close to that of a single-action 1911 but in a polymer striker-fired pistol.
Lowers pull weight to between the 3lb and 4lb mark
Smooth uptake and reset with crisp break
Reduces overall trigger travel approximately 50%