you get what you pay for jim, i'd go for bigger than 5 litre, i have (i think there!) 8 litre orions, there all right. cleansmart sell them, around £55 to £60. i've had 1 year out of one and nearly 2 years out of another, pump ups gone on one but i swap it from the other one. theres a lot better out there but you can pay up to around £250 i think. like i said mine are all right and at £60 there good value for money, don't get the £10 cheapo's from local stores. they won't last 5 mins and they take half an hour to prespray one carpet, time is money so the savings in time on the job far out way the initial outlay.