Our Unit 1 is designed for extreme accuracy. Unit 1's are supplied with a test target showing they shot better than 1"@ 50yds (5 shot group). This super reliable unit has a slide machined from billet 7075 aircraft grade aluminum or steel. They have an interchangeable sight rib allowing the user to configure it with adjustable sights, a scope rib or the combo rib which has both capabilities. The sight rib mounts directly to the barrel creating a rigid fit between sights and barrel. Our Match Grade barrel also gets locked down directly onto your 1911 frame via our machined steel slide stop. Couple that with our hardened steel breech insert, steel barrel lug, steel recoil guide rod and you have a super durable conversion capable of "World Class Accuracy". It's designed to shoot standard velocity 22lr ammo but can be tuned for high velocity 22lr ammo also by changing out the recoil spring. Comes with 1 magazine, slide stop, takedown tool, instruction manual and case.