Gas Availability in France and Spain.

I currently use Calorgas Propane and have two 6Kg lightweight bottles which is great in the UK. However when we go to France and Spain I will probably run out and need to use a different gas. I understand that there is an adaptor that can be used from the existing system and uses a continental gas suppliers bottled gas. Can anyone tell me more about this and where I can get the adaptor.

Thanks