Hi Smurf,I use this pump box, I've had it about 2 years now. I have a weeks worth of window cleaning so it's not worth buying a mobile system. When I pressure clean I detach this from my trolley a take a drum of pure to clean windows afterwards. I've put everything through it - Hypo, weed killer, DDAC and its still going strong. It pumps enough for render/roof cleaning, just take a little longer.http://www.ebay.co.uk/itm/Pump-box-pack-economy-van-system-or-backpack-alternative-Includes-charger-/141444432641?hash=item20eebec301:g:324AAOSw1x1URVKCAndy