It's a tactical rail on the upper receiver and an adjustable stock. The DEF10 has a single phase trigger and comes along with a single twenty-round Magpul PMAG. It has an MSRP of $999 as well as comes along with ArmaLite’s limited life span warranty.You got it correct. It is a screw-on choke tube. It is really a minimum of much like the Lyman/Cut