Copeland 918 0056 08 Crankcase Heater 321894 708 Rugged Construction: Industrial grade materials resist Rugged Construction: Industrial grade materials resist vibration and environmental stress common in outdoor condensing units It is highly recommended to inspect or replace the condensate safety switch during the swap to ensure the system will shut down if the primary drain line ever clogs in the future Optimized Performance: Helps maintain system efficiency by reducing mechanical wear during the most critical part of the cycle: the start it eliminates the risk of oil dilution and catastrophic liquid slugging upon startup