This O series medium universal-mounted temperature control has an automatic reset, close-on-rise SPST switch. It has a temperature ranging from 25 to 75 degrees Fahrenheit and an operating voltage of 120V AC. The temperature control measures 3 1/2 width x 2 3/4 height x 2 inches depth with a capillary length of 72 inches and a bulb diameter of 3/8 inches. It meets the UL standard.