The pressure gauge worked the first time when I first received it in October. I used it yesterday for the first time since first use and noticed that it now leaks air from the other end of the pneumatic attachment when the sensor is attached to the tire valve. The small steel ball in the gauge shaft, which is designed to prevent air escaping from the unused side of the gauge when the gauge is placed on the tire valve, does not seem to be seated properly or tight enough against the rubber seal in the gauge tip to close the gauge form. useless as it does not register readings on the display. Very disappointed and a waste of money. I had high hopes at first as the sensor had an easy to read display and an LED backlight that illuminated the tire valve in low light conditions.