M2 Armament Group AR-15 Mil-Spec M4 Stock Black. Designed to deliver dependable shoulder indexing rapid length-of-pull adjustment and lightweight durability this iconic waffle-style stock is an essential component for custom rifle builds duty carbines and general-purpose AR-15 assemblies. Specifications for M2 Armament Group AR-15 Mil-Spec M4 Stock: Manufacturer: M2 Armament Group Color: Black Gun Model: AR-15 Stock/Brace Material: Polymer Gun Type: Carbine Length of Pull: 10.3 - 13.8 in Weight: 8.4 oz Length: 6.7 - 8.5 in Hand: Ambidextrous Buffer Tube Size: Mil-Spec Gun Make: AR Platform Finish: Matte Package Contents: M2 Armament Group AR-15 Mil-Spec M4 Stock What firearm models does the manufacturer say M2 Armament Group AR-15 Mil-Spec M4 Stock is compatible with? The manufacturer says that M2 Armament Group AR-15 Mil-Spec M4 Stock is compatible with AR-15M2 Armament Group LP-Stock-M4: AR-15 Mil-Spec M4 Stock Black