Are all 12g unthreaded cartridges the same? Or are they different sizes?

Well funnily enough I e-mailed the guys at tyreinflators.co.uk about this. Last time I bought from them I bought unthreaded 16g cartridges for an innovations pump, this time when I went to buy it says ‘these don’t fit innovations pumps’. So I mailed them and got the response that their unthreaded cartridges have a slightly smaller fitting than innovations one which means they might leak. But all threaded ones are the same. So there’s your answer.

I think they are all the same, dont buy them in a bike shop, they cost a fortune. Have a look here http://www.tyreinflators.co.uk/shop/ I pay 45p each (for 30 x 16g) Evans will charge you £1.95 each.