I bought 2 of these sensors 3 years ago and they were very good. One of these had the air pressure relief valve failing rendering the product unusable so I ordered another. The day I received it I tried it and after 2 quick uses the valve failed. I was very disappointed as I really liked the product. I returned the product and bought a Jaco pressure gauge and really liked it. Maybe I just got a bad one, but I didn't dare to order another one. BTW, the other slime sensor I have still works.