As a mechanic, this product blew my mind. Based on my observations, it`s incredibly accurate and efficient when checking engine timing .The tool is easy to use and fits perfectly for Chevrolet Malibu and Excelle models. The pros are that it saves time and money, and it's a perfect addition to any automotive tool kit. The cons, however, are that it is not compatible with all car models and can be tough to find in stores..See full review