How to use the AA Digital Tyre Pressure Gauge
Remove dust cap on the tyre valve and place the head of the digital tyre pressure gauge over the tyre valve, pressing firmly. Press the On button and hold gauge on the valve until the reading on the LCD display locks. Remove the gauge quickly and take the reading. The gauge will automatically turn off 30 to 90 seconds after use to save the battery and extend the battery life.
works on the included 3 x Button cell AG13 or LR44 batteries, To replace the batteries, you will need a small diameter Phillips screwdriver to unscrew the two screws which hold the two halves of the case together. Easy enough!