VINTAGE UNTESTED CIRCA 1950 ANALOG CLOCK BASED PROGRAMMABLE THERMOSTAT WITH BOX (IN BAD SHAPE) AND ALL PARTS AND ACCESSORIES NEEDED FOR INSTALLATION. HONEYWELL TM-850-A,  OWNER'S MANUAL PRINTED 7/1970 MAY NOT BE FOR THIS MODEL BUT IS AVAILABLE ON GOOGLE. WALL HEAD UNIT IS 4 3/4" X 2 7/8" X 2 7/16".

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