Includes: AR receiver block (P# ARRB), folding stock mechanism with 1 1/4" sling mount (P# FSM-SMG), M4 SOCOM Modular with lock ring and CAR stock adapter (P# M4M), and all mounting screws. A CAR lock ring, spanner wrench is useful for installation, and is not included, see below to purchase.

To use a ACE Modular folding stock on a standard AR15 receiver, you must use an alternate recoil system like ZM LR300 or .22 LR converstions. No modification to receiver is necessary.