The ELF Drop-In Match Trigger has been built for law enforcement and military duty. The only AR-15 trigger using aerospace grade sealed bearings, making for an incredibly smooth and fast trigger pull. Our exclusive .043 double double wound polished piano wire hammer spring ensures full ignition of any ammo including .308 and 7.62x39. Pull weight from 2 3/4 to 4lbs is so easy to adjust it can be done in seconds without removing the trigger from your lower receiver. A second-to-none AR-15 drop-in trigger system that is strong and light, made of wire EDM machined, hardened A2 tool steel and lightweight aircraft-grade aluminum. Installation can be done in minutes using your AR s original hammer and trigger pins. The Match trigger may be ordered with a curved or straight shoe. Fits any mil-spec AR-15 Incremental Adjustment Knob Absolutely Drop-Safe regardless of pull-weight Adjustable from 2 3/4lbs to 4lbs without removing from lower Proprietary Double-Double torsion hammer spring and heavy hammer ensure proper ignition of any ammunition Very short pull and reset allows for rapid follow up shots and greater accuracy Sturdy trigger assembly designed for rugged, trouble-free use; Made of lightweight aircraft-grade aluminum and hardened steel Unique design of disconnect allows full 1/4 width eliminating possibility of wear and double-firing High performance trigger and hammer needle bearings for smoother and faster firing 100% made in America with a Lifetime Guarantee!