Are you thinking about build a new AR-15 rifle or completing that lower you have had sitting around for months? Do you need to replace that fixed stock with a collapsible? Well then look no further that this CMMG M4 receiver extension for your lower. The perfect way to complete your build, the CMMG M4 buffer tube is mil-spec diameter and will work with all standard pattern AR-15 lower receivers and any mil-spec diameter stock.

Specifications and Features:
CMMG AR-15 Receiver Extension M4 55CA9D7
Compatible with all Mil-Spec diameter stocks
Aluminum
Hard Coat Anodized Finish
Matte Black