It is an English pressure barrel. I have a 25lt version made by Boots in the UK. Apparently they are or were quite popular in the UK. I bought mine about 15 years ago and have only used it a couple of times. You need to carbonate by priming with sugar/dextrose and use small soda bulbs to dispense. If you look at the lid it has the fitting for putting the soda bulb in. I found it was not very successful for australian type beer conditions i.e. highly carbonated lagers at cold temps. It is probably better suited to low carbonated english style ales consumed at cellar temp.
:beer:
Mothballs