The new Power Save Timer, Model 091-191-115 introduced by Kussmaul Electronics, is a timer for block heaters that limits the duty cycle of an air conditioning load to one hour "on" and one hour "off." The Power Save Timer reduces the "on" time to 50 percent, thus cutting power consumption from your 110 volt block heater in half. A bypass switch may be installed to permit fulltime operation when full power operation is desired. The Power Save Timer comes with a three-year warranty.