Saves time especially when your TPMS isn't telling you which of your tires is the problem. I restore Jeeps as a hobby and my newest, a 2012 Wrangler Sahara has TPMS but only a light on the dash tells you there is a problem, not which tire has the problem. After I had confirmed that the air pressure was correct, I was able to use this tool to determine very quickly which sensor was bad and I got the sensor here at Revain for little money and replaced it myself. Yes the tool is quite expensive but right now every car in our family has TPMS so I expect to use it many times in the future. It will most likely pay for itself after about 2 uses, not in a tire shop.