lpk and hpa/co2

You could buy a LPK for your A5, and run C02, but I wouldn't recommend it. You would with out a doubt need an anti-siphon tank and a Palmers stabilzer.

If you buy an HPA tank, you don't need anything else. Simply screw it into your ASA, and away you go. It's that easy.

A Low Pressure Kit reduces the amount of air that is needed to fire you gun. All HPA tanks have a built in regulator that reduces the PSI down from 3000/4500/5000 PSI to what your gun shoots, around 800 PSI or so. A LPK has a new valve, springs and regulator that allows your gun to shoot around 500-600 PSI. The benifit of this is that it is quiter, less recoil and easier on air. Unfortunately, it's also kinda expensive. You'd just be better off buying an HPA tank and a good regulator.