Generic 1. Insert the battery with the "+" terminal facing up. Open the tire tread depth gauge. Place the base on a flat surface and press the strip downwards. When the zero button is pressed, the LCD screen will display 0.00! Place the gauge on the tires, hold it steady, and press the tip of the rod into the tire tread. Read the tread depth value directly. Test several times for accurate measurement. Turn off the gauge; please remove the battery when not in use for an extended period. Tire Care Product