WAVE technology offers hygienic touchless operation on command. Activating only when a hand is waved directly over the flushometer, the sensor eliminates random flushing that can be frightening for children. And by removing false actuations, Wave technology provides even greater water savings. Fixture-mount design. Includes 1.5 V AA batteries. Retrofit models require a control stop and vacuum breaker. Intended for toilet installations with 1-1/2" spud coupling connection. Brass construction.