ET Arms Plum Crazy AR15 Pistol ETAGPCPMM556ML7. This AR15 Pistol is chambered in 5.56NATO and features a 7.5" barrel with a 1:8" twist. Key features include a Gen II polymer lower receiver that is lightweight and ultra-durable, a 7" MLOK handguard with enough room for all of your tactical accessories and flip-up sights. This pistol will allow you to add your favorite pistol brace to increase accuracy and stability. This compact and lightweight AR15 Pistol is great for home defense or a fun range shooter. Grab one today.