Wilson Combat TRTTUH2 Tactical Trigger Unit Two-Stage Howe Two-Stage Drop-in Trigger with 4.5 - 5 lbs Draw Weight & Black Finish for AR-15The Tactical Trigger Unit is an all new modular trigger unit that can be easily installed in any AR pattern rifle by the end user in less than 1 minute without tools or even removing your selector. Wilson Combat has created a drop in trigger unit with an ultra crisp trigger pull that does not require any fine tuning or adjustment by the end user, the TTU is a totally self contained trigger module.