As sent in by Simon Lee of MadBull Airsoft yesterday. This item costs around US$20-25 (not final pricing yet)... "The RAS rail system on the real firearms is fixed on by via gas tube. AEGs don't have gas tubes to connect both RAS and upper receiver. RAS FIX is a new product which mounts on both the upper receiver and RAS. It will make your RAS and upper receiver connected tightly. It can also be used as a scope riser mount. Compared to version I, Ver. 2 is shorter and cheaper."