I bought this on sale a few years back and I found it more of a chore to use.  The plastic tip does not create a good seal on the valve stem and It usually takes me 2 sometimes 3 times to get an accurate reading.  I think this could be avoided if the tip was metal.  Also, there is no bleeder valve, so if you're tires are overinflated, you need to do more work.  I personally use the Accutire MS-4021B which I find far superior and it's way cheaper.  Strangely, it's cheaper but more ergonomic and practical as it has a nice thumb rest to help you get a better reading and it also has a rubber grip.  Personally the best gauge from experience is one of those analog ones that have a built in bleeder and have a filler chuck so you can fill the air through the unit and bleed off whatever you don't need.  Trust me it saves you a lot of time.  But if you insist on one of these digital gauges, I recommend the Accutire MS-4021B.  It's cheap, it works, and it's more practical.  I give the MS-4000 2 stars because it wastes my time and there are better products out there for less.