Buttstock Kit, Carbine, M4A1, Type II-B, (4-2)

Colt Buttstock Assy, Type II-B - with sling swivel (Current Production).  CAGE 4U486.
Colt 4-Position M4 Receiver Extension 
Colt Receiver Extension Nut 
Colt Receiver End Plate 
Colt Action Spring, 17-7PH Stainless Steel 
Colt H2 Buffer Assy