SELF-FLUSH: it will flush automatically through infrared detection units. SAVING ELECTRICITY: Its power is supplied by Four AA alkaline battery (NOT INCLUDED), which is not needed to replace in two years if its usage frequency is 3000 times a day INDUCTION DETECTION: 80cm-85cm automatically Adjusted CLEANNESS AND HYGIENE: Flusher Works automatically because of automatic sensing appliance, without touching any metal parts, flushing completely without peculiar smell and eliminating effectively mutual infection of bacteria.