This battery operated "on demand" wrist strap tester evaluates wrist straps with a single touch at the workstation. Simply plug your ground cord into the banana jack and touch the metallic surface of the tester. A path for current flow is completed from the your skin, through the wrist strap. This action will cause the green "PASS" LED to light as long as the operator-to-ground resistance is between 800KΩ and 10MΩ. If the wrist strap fails, the red "LOW" or red "HIGH" LED will light and an audible alarm will sound. The tester's portable small package allows a supervisor to spot check users on the shop floor. Comes with 9V battery and NIST-traceable Certificate of Calibration.