Wilson Combat TRTTU3G Tactical Trigger Unit 3-Gun Drop-in Trigger for AR-Platform. A single-stage trigger unit designed for quick installation in AR-pattern rifles. Delivers a 3.50–4.0 lb draw weight with an ultra-crisp trigger pull and a reliable reset for fast follow-up shots. Pre-assembled CNC machined trigger housing contains H13 heat-treated trigger, hammer, sear and a stainless steel spring for trouble-free installation. Drop-in AR trigger compatible with standard GI trigger pins of .154 inch diameter. Not compatible with Colt rifles with pinned-in sear blocks; MR556 ARs with firing-pin safety in the bolt carrier may require the TTU 3G model. Finished in Black.