Most sites still run on co2 (A HPA system is expensive to install and not really cost effective for smaller sites ) you only generally get sites with HPA systems if they do walkons or other events though some sites will get air in bottle form for walkons instead of owning and running a system.Cheers for the advice , I've already ordered my mask and and bought a second hand rotor. Il probo keep an eye out for a second hand speedball style marker,. Also What's the score with filling bottles at sites? Is it mostly air they provided. I think my nearest sites combat paintball in northwold or thetford.