Self-contained drop in trigger. Lightweight 6061-T6 CNC Machined aluminum housing with Wire EDM cut, Heat treated Tool steel trigger and sears. Featuring a double sear design. Two position, trigger blocking side safety. Fully adjustable Sear Engagement, Over-travel, and pull weight from 8oz.-2.5lbs. Available in blue(black) and Nickel Plated. Teflon nickel coated Sears to guarantee a lifetime of reliable service. Mfg: Timney