Where can I get an air horn refill in Ireland?

I have all the other bits and i am taking part in an activity were i need to make as much noise as possible. All i need is the gas for it and i would like to know were to get it(preferably munster area)?

Any car shop around Cork City. Under a tenner. I'd normally get them in the car shop up stairs in Merchants Quay.

You will get them in Halfords.

Thanks lads will try them later