For use with motors with dynamic parking, including Robert Bosch and Sprague Devices motors. Sealed construction, including O-ring on the shaft. Black plastic knob with metal insert and set screw , white imprint. Mounting stem 7/16" -28 thread, .45" (11.4mm) long. Diecast case 1 5/8" (41.3mm) diameter. 6 blade terminals.