Review on Accurate and Convenient Tire Tread Depth Gauge Tool by Preciva, LCD Display, Inch and MM Conversion (0-0.98 Inches) by Daniel Truett

Great gadget for your car's toolbox. Accurately measures the remaining tire tread. Fast and easy to use. It is small and easy to store. It has a strong feeling. The dimensions are fairly close to one inch (25mm). Alternatively, you can measure the depth of the bolt hole or any hole. Pretty useful little device.