BCM Pistol AR15 Lower. Comes with everything shown in the above pic to include the BCM QD plate and BCM PNT. 

SPECS:

Machined from Aluminum Forgings 7075-T6
Hardcoat Anodizing: MIL-A-8625F, Type III, Class 2
BCM® Milspec 7075-T6 Pistol Receiver Extension (1.2" outside diameter. Fit the ATF compliant SigTac SB15 type pistol stabilizing brace. Works with carbine buffer and action springs.
Staked M4 Lock Nut
USGI H Buffer (1 USGI Tungsten, 2 Steel)
BCM Trigger Guard
Low Shelf for RDIAS installation
Low Shelf for Accuwedge use
Un-notched Hammer compatible with 9mm use
Fire Controls marked SAFE and SEMI