I found this product to be accurate and everything that it is claiming to be. I used it to identify a GPS trackers on my vehicle. It is a very sensitive device, so when you are using it, it is best to have an area where there is no or little background influence. For instance if I was in the parking lot checking my vehicle for tracking devices and If there was someone using a cell phone in the car as they drove by it would affect my readings. I am very pleased with the product, and would buy from SpyGuys again.