It has a RAP4 Universal Bi-pod, a RAP 16" Tactical Barrel, RIS Handguard, 7/8th inch M4 front-sight and RIS Muzzle Brake, a RAP4 MR1 M4 Carbine stock, ESP Rocking Trigger, and a Barska 1x50mm Red-Dot sight.
I haven't been able to test the barrel out, but it's a little different than my previous barrel, Smart Parts Progressive 14". It has grooves on the inside of the barrel so i'll see how that goes.
The stock does fit the MR1. It replaces the velocity adjuster and gives a good sight line even with a mask because it's a wee bit lower.
I have a M4 mag expansion chamber from RAP4 that I haven't put on yet because it doesn't fit on to the gun but the part that attaches to the drop-forward does fit on. The screws on the drop-forward stripped so I need to get those off.
I am also going to get a grenade launcher for under my barrel on the RIS rail. Which would work better the short or the long grenade launcher?