I had one of the digital sensors from the 80's. Was still working until a friend borrowed it and took it in the trunk only to smash it. A good friend would replace him. But good friends and good gauges are hard to find. So I bought this technology in hopes that it could be made into a cheap, durable tool. I was wrong, the batteries died after a month and in just two uses. Not like my sensor from the 80's which had 25 years of battery life (no kidding). I didn't like taking this unit apart to change the batteries because it's not as fast as a TV remote. if it worked, it worked.