We bought 2 pieces, one for me and one for my girlfriend, for use on regular tires of medium displacement cars. So, the device as a device seems to do its job given that you will use it in an emergency... but BE CAREFUL because its plug is made of low-quality plastic and I say this because as soon as we put it for the first time in the cigarette lighter socket it broke and got stuck inside the hole, so we had to go to an electrician who put in another plug, clearly of better quality, costing us an extra 10 euros for each piece, that is, 20 euros in total. So, I would suggest that before you buy any other air compressor, at least make sure of this very important detail.