MAXI 110 beer cooler - read lots of threads but don't understand what it is : (

[GabrielKnight]

I'd be extra grateful if you could explain in some detail:

1. exactly how these work ?
2. how much maintenance, ice / water top-ups they require ?
3. How much they can cool / adjustable to cool less they are ?

I'm at the stage where I'm producing tasty stuff in polypins, have a beer engine with a 'cooler jacket'. Where would one of these fit in?

Sorry to seem thick! I'll buy one straight away if its what I want, but don't want to spend £££s without understanding what I'm buying!