sarah, sorry to contrdict Ian, but we only use the connection that plugs directly into the side of the van and have had no problems with it. We do have the ballvalve assembly that fits into the side of an Aquaroll (which is damn expensive and could be made fo a fraction of the price). However, with this setup you need to lug the 'roll around with you which is not too bad if you emain in one place but for touring it is a pain. Thus, when we use a super service pitch we leave water and waste containers behind and can set up in very little time. So there is the advice of a satisfied user of the direct plug in - and we do not seem affected by low pressure otherwise, I would be told to tak the 'roll and ballvalve assembly.