The TST Orange Drop-Ins help control unwanted odors and break down waste and tissue in your black water holding tank. The easy to use drop-ins contain a special chemical that helps break down waste, and a blend of citrus-scented surfactant oils that trap unwanted odors in your tank, making your camping experience more enjoyable. The drop-ins are RV and marine approved, non-formaldehyde and safe for all septic tanks—they’re even great for portable camping toilets! Each bag comes with 15 drop-ins. 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