The Manitowoc 76-2781-3 Ice Machine Thickness Probe 4" x 3-1/4" is designed to accurately monitor ice thickness in compatible commercial ice machines, helping ensure consistent ice production and optimal operating performance. It by detecting the thickness of the ice as it forms on the evaporator and transmitting precise signals to the control system, which initiates the harvest cycle... https://partsfe.com/76-2781-3-manitowoc-probe-ice-thickness