【High Quality materials】water-resistant Infrared motion sensor prevents moisture or any accidental spills from damaging the unit.【Advanced technology】 delay sensing technology preserves battery life and prevents any unnecessary opening from pets, children, or walking by.【Touch-free motion sensor lid clouser】seal odor in and eliminate cross-contamination of germs. Requires 2 AA batteries (not included), alkaline battery highly recommended for best performance.【Ease and convenient】removable ring liner holds trash bag sturdy in place and prevents bag from overhanging for a neat and clean appearance. Use any standard trash bags or Ninestars custom trash bags NSTB-3-30.