Just received it today from Amazon and took it to the garage to try. It was easy to use: Plug it in, attach to your tire, turn it on and select PSI by pressing the “on” button repeatedly. Set the air pressure you want with the “+” and “-” buttons, press the trigger and it adds exactly the psi you want and then stops. This item works as advertised. I used it to air up all four of my tires and the whole process took less ten minutes.