Choate Tool M-16/AR-15 E-2 Butt Stock223 5.56. I. Stock. Made of tough fiberglass polymer. This is the same material the army uses on their rifles. Our stock adds 3/4? to the length of pull and almost doubles the amount of storage space. This stock also features an Off Hand notch to grasp when firing from a prone position using a bipod. A butt plate is not included.The G.I. issue butt plate fits the stock. Specifications for Choate Tool M-16/AR-15 E-2 Butt Stock: Manufacturer: Choate Tool Color: Black Gun Model: M16 AR-15 Condition: New Country of Origin: USA Features of Choate Tool M-16/AR-15 E-2 Butt Stock M-16/AR-15 E-2 Butt Stock Package Contents: Choate Tool M-16/AR-15 E-2 Butt Stock What firearm models does the manufacturer say Choate Tool M-16/AR-15 E-2 Butt Stock is compatible with? The manufacturer says that Choate Tool M-16/AR-15 E-2 Butt Stock is compatible with AR-15 M16Choate Tool CMT-16-01-02: M-16/AR-15 E-2 Butt Stock223 5.56