Four (4) Size AA Battery Back-up Power Source "Low Battery" Flashing LED PERMEX Synthetic Rubber Diaphragm with twin linear filtered bypass and vortex cleansing action Flex Tube Diaphragm designed for improved life and reduced maintenance ADA Compliant Sloan Solis Solar Powered Infrared Sensor for automatic "No Hands" operation Infrared Sensor with Multiple-focused, Lobular Sensing Fields for high and low target detection Engineered Metal Cover with replaceable Lens Window User friendly three (3