Install AutoFlush® Clamps in a minute without turning off the water! Simply fit the unit over the existing handle, secure two mounting screws and replace the cover. Keeping fixtures flushed and presentable couldn't be easier. Both Urinal Clamps and Toilet Clamps are available. Cam gears provide trouble-free operation. Sophisticated sensors deliver dependable activation. Programmable flush options allow daily flushing to prevent sewer gas buildup. Audible tone option indicates low batteries. Runs for more than three years on four C batteries (included). Toilet Clamp No. 121739 is equipped with a manual flush button, ideal for rinsing after cleaning.