Lidl will have one on sale soon. It's £13, which is nothing. On the other hand, the house is cluttered with crap like this on a "oooh, look, that's well cheap that, might need it one day." So lots of stuff gets bought and sits there or is only used once or twice before I trip over it, swear at it, eBay it or try to give it way. Neither myself or my folks ever filled a diesel with petrol or vice versa.