With the Warsport LVOA M4 getting its airsoft version, with Krytac soon releasing their licensed version and G&G with their own take on the design, RA-Tech and Angry Gun teamed up to make their own. Thus, the RA-Tech Angry Gun Custom Warsport M4 Gas Blowback Rifle that has the front end from Angry Gun, Inner Barrel and Hop-Up Rubber from RA-Tech. It's an assortment of parts to put this together with some coming from GHK too.