Airtech Studios G&G ARP9 / ARP556 BEU Battery Extension Unit Factory Replacement Parts (OEM) The rear sight is easy

The rear sight is easy to flip up and down

and work in any gun Version 2 or Version 3 compatible parts

Compatible with all airsoft M4 type guns

Output Energy: 1-3J Adjustable (build dependent)

Uses a Tamiya connector

Airtech Studios G&G ARP9 / ARP556 BEU Battery Extension Unit Factory Replacement Parts (OEM) The rear sight is easyThe Airtech Studios G&G ARP9 ARP556 BEU Battery Extension Unit is designed to fit on G&G ARP series of AEG guns: fits on the ARP9 and ARP556. Very easy to install so you can add longer and bigger batteries in your rear stock buffer area. With it installed, you can use 9. 6v 1600mah nun chuck, and any longer 11. 1v batteries in it, with extra room to spare. This is a must have for those that want flexibility with battery space. For the ARP9 and ARP556,