Sloan Optima SMO EBV 89A-METAL Auto Flush Valve Battery Powered, Sensor Operated Auto Flush Retrofit Conversion Kit for Exposed Closet and Urinal Flushometers. Sloan OPTIMA SMO equipped Flushometers provide the ultimate in sanitary protection and automatic operation. There is no need for AC hookups or wall alterations. The Flushometer operates by means of a battery powered infrared sensor. Once the user enters the sensor's effective range and then steps away, the Side Mount Unit initiates the flushing cycle to flush the fixture. User makes no physical contact with the Flushometer surface except to initiate the Override Button when required. Helps control the spread of infectious diseases. 24 Hour Sentinel Flush keeps fixture fresh during periods of nonuse. Automatic operation provides water usage savings over other flushing devices. Reduces maintenance and operation costs. Installation and battery replacement does not require turning off water to the valve.Sloan - Optima