12.5-13.5" skinny hammer forged barrel, DDliteweight freefloat rail 10", adjust gas block ala noveske switchblock, upper & BCG Failzero components, AAC can. mags with uber springs, trigger that doesn’t suck. Atpial & IR scoutlight afixed with the dual tapeswitch. ergogrip. moe buttstock. and some decent dam mags
Stick with standard A2 Grip, and I’d dig it. 
Glad to see my Switchblock went to such a worthy build.
Your gonna cut the DD rail I take it for the Switchblock?
Pics, or it didn’t happen. 