As other reviewers have stated, you will have great difficulty simply getting the air hose on and off the tyre valves, a task made worse by the fact the hose is far too short. On a cold day with what feels like someone else's hands, it is simply not possible to pull the connector off a valve without losing two or more seconds of air. This is because the connector is of very poor quality, and is very poorly finished as well. It is not metal like you might find on your local forecourt but cheap feeling plastic.
The gauge on the unit reaches to a stratospheric pressure nobody in the real world wants (300 psi) meaning the more ordinary numbers you do (20-40 psi) are crammed together at the start of the dial and are impossible to read accurately. A twitch of the needle covers a huge range of pressures and the unit over-reads by 10 psi when the pump is running, making it a game of switching the thing on/off to see when the pressure is right.
On that subject, pumping the rear tyre on my wife's car to 32 psi and then checking with an external digital gauge showed it had been over-inflated by almost 6 psi, and others here on Amazon alone have reported even wilder discrepancies. So it's outright dangerous too.
While it does do the job of inflating tyres very well, and being 240V - the main reason I chose it - you have no fear of draining your car battery, and while the pressure stays good, strong and constant throughout, it is dangerously inaccurate and broadly worthless because of that.
Ring is a British company.