Short and simple: Works as advertised. I didn't need a $300-400 car to find a simple auto freon leak. I don't make a living from it and may only use it a few times in the next ten years, so basic/cheap is fine. A leak was found where the heater hose rubbed against the air conditioning intake line. The truck was statically leaking about 4 ounces of freon per week. I tried the coloring route first but didn't see anything. The snooper found him in a minute of searching. If it never works again, it costs money.