First proof of purchase failed to blow up kids pool toys. I used lung power and forgot until I pumped up the tires on my grandson's bike. I wasn't allowed to give ZERO stars so please forgive me for giving them as it was a total FAILURE! The pump makes noise, the pressure gauge stays at zero and the tire has actually lost air! The system is clunky, the aerial cord compartment door doesn't close properly, there are separate AC/DC power cords, an AC/DC toggle switch, and a separate AC/DC power switch. It's not convenience, it's just a complete FAILURE.