Just bought a jump starter pack and only now thought of it if it’s able to be stored in a car to be called upon if necessary as if it’s not then there’s not much utility in a ‘portable’ jump start Pack. The one in question is the Top Tech 3-IN-1 12V Booster Pack with Air Compressor
Those are quite big. I keep a NOCO booster in the glovebox, about the size of a paperback book (no use for inflating tyres, of course, but I’ve never had the need).