RS PRO Wrist & Foot ESD Tester RS Stock No.: 733-996 RS PRO Wristband and Heel Grounder Testing Station The RS PRO Compact Tester series can be used to test personnel wrist straps and footwear for measuring a static charge. The tester uses either red or green LEDs and an audible alarm to indicate whether the measured resistance is within the range specified by EN 61340-5-1.