Stores maximum compression value for up to 12 cylinders. Backlit LC display is easy to read from any angle and in any light. Uses standard 9V battery for convenience and cost. Automatically shuts off after 3 minutes of non-use (memory is retained). Rubber boot protects the gauge from bumps and drops Sealed, grease and oil-resistant gauge face prevents contamination of electronics. Displays values in PSI, Bar and kPa. This comprehensive diesel engine compression test kit features am electronic tester that memorizes the peak compression value for each cylinder. When testing is complete, the values can be quickly reviewed at the push of a button.