AKA Aluminum Recoil Spring Guide Plug Light is made specifically for the Marui Hi Capa 5.1 GBB Series. The gaps may make it look flimsy but the fact that it's made of high grade aluminium means that it can withstand quite a battering. You can either get it in gold, silver or red!
Please note that all aftermarket products may require professional installation. For increased compatibility, please use consistent aftermarket branded parts to upgrade your GBB, or consult your local gunsmith.