Bravo Company Stock Hardware Mount Kit, Fits AR Rifles, Mil-Spec Buffer Tube, Stock Kit Contains Buffer, Tube, Spring, & Hardware, Black BCM-STOCK-HARDWARE-KIT Bravo Company's BCM Mil-Spec Carbine Stock Hardware Mounting Kit for AR-15's contains all the necessary parts to mount your Mil-Spec dimension stock assembly to your lower receiver- Receiver Extension (Mil-Spec" 6 position)" Receiver End Plate" Castle Lock Nut" M4 action spring" carbine buffer assembly. This kit is compatible with the collapsible stocks from- BCM" VLTOR" LMT" Magpul CTR-M" Stag Arms" Colt and others.