This slime gauge is pretty good overall. I bought it as a supplement for about $5; for the price it's worth it. Over the years I've kept various digital tire pressure gauges in the glove box of each of our machines and use them once or twice a month to maintain proper pressure. If you live in a place with four seasons, temperature changes can deflate your tires and we all know that this leads to uneven wear, reduced fuel consumption, reduced tire life, bursts, etc. Below are the PROS and CONS of this sensor: PROS: Backlit display easy to read even at night Backlit valve ring makes it easy to set gauge accuracy; I measured the pressure simultaneously with three different gauges and all gave readings within 0.5psi. Works well at high and low temperatures. Very easy to hold thanks to the rubberized handle. see display Requires an on/off switch, not activation by placing a pressure gauge on the valve stem. When the batteries run out, this pressure gauge will be sent to the bin. The backlight stays on for a long time after use, which can drain the batteries faster (it's better to turn it off with the button after the last read). So it's a handy little sensor that should be an option for most who need a car, bikes (Presta), snow blowers and the like. My favorite is still the Accutire MS-4021B as this thing is well designed and has been a workhorse for about 6 years, but this digital slime meter costs a little more than a basic pencil meter and is a good choice too.