ARES Amoeba Pro Beavertail Backstrap Grip for Ameoba & Ares M4 Series AEG
Polymer Construction
Suitable for Ameoba & Ares M4 Series AEG Rifle
Also fit any of the older and newer model ARES M4 AEG

Disclaimer: All aftermarket upgrade parts require necessary skill or modification to install and assemble, please consult with your airsoft technician if needed.