This piece is designed to convert Airsoft so-called AUG A3 models into proper A3s. Currently all full size Airsoft A3/A4 variants by JG, ASG, APS and others feature a rail taken right off the A2 model with an added front piece however everyone seems to have forgotten to add the proper upper rail supports to complete the A3 look. So since I was fixing up my JG AUG I created a 3 part kit that solves this problem. The rear piece here simply slides in from behind under the overhanging rail and is friction held in place. Additionally it can also be bolted down for a more secure fit. Check out the video below for details. To complete the look, check out the front pieces, also on my store, that fill in the gap near the charging handle. Please note this was designed specifically for the JG brand of the AUG A3, this piece will likely fit other brands and the A2/A4 model but from what I've seen the rear overhanging rail does not go as far so it might make for a strange result on other brands.