Feature●Tire hardness can alter your cars performance - a tire too hard wont bite and a tire too soft may wear quickly or even ball up●This easy-to-use tool will quickly, accurately, & easily help you keep track of your tires hardness, allowing you to maximize your potential on-track●Features a straight edge on base to rock durometer for more consistent results and includes a non-slip coating for a comfortable and improved grip●Reads from 0-100 points (shore A scale) and comes complete with a calibration test block, hard case, and storage pouch●For consistent results, rock the durometer from angled back, past straight up, to angled forward, and the readout will move up to the highest readingDescription Longacre 50547 Digital Durometer With Silver Case .For the most consistent results rock the durometer from angled back past straight up to angled forward. The readout will move up to the highest (true) reading, then back down. Record the highest reading reached. The durometer must have a straight edge on base to do this properly. If you just push straight down you may get inconsistent and inaccurate results.