Resealable bag contains 15 Drop-INS; one Drop-IN treats a 40 gallon tank. Easy-to-use, ultra-concentrated granular formula. Environmentally Safe! Product Features Eliminates odors and helps break down waste in the RV holding tank Ultra-Concentrated: just one drop-in treats up to a 40 gallon tank Does not contain the toxic, formaldehyde-releasing ingredient bronopol RV and marine approved; Safe for all septic tanks Fresh citrus scent, 15 drop-ins/bag