This citrus-scented InSinkErator® Bio-Charge® Cartridge Replacement for Evolution Septic Assist® disposers is a cost-effective enzyme treatment. Bio-Charge contains a natural microorganism that helps break down food waste and a citrus scent to help control odors from the sink and drain. Bio-Charge® is only for use with the Evolution Septic Assist disposer, and will last 3 to 4 months with average use. One cartridge of Bio-Charge® equals 4 bottles of other septic treatments.