We have one of these on the static. Don't use it as there is quite a bit of gas left when changeover device says a bottle is empty. This is important to us as gas is the single most expensive item (next to the rent) and you have to maximise what you get. In winter when not using the changeover unit we get up to 3 more days. When a bottle only lasts 10 to 12 days in a cold period when the central heating is in use you can see 3 more days is quite a gain. We found this out on our last site (150 vans) where no one uses the auto changeover for this very reason. Hope this is helpful to anyone who has one of these devices.