Rhino Holding Tank Cleaner Drop-INs - 6-PackCamco’s Rhino RV Holding Tank Cleaner Drop-INs contains a powerful enzyme complex that helps clean your RV’s black water holding tank. Just (1) Drop-IN treats up to a 40-gallon tank. Cleaning your holding tank regularly helps keep tank sensors functioning efficiently and keeps unwanted smells at bay. These easy-to-use Drop-INs are pre-measured and safe for all septic tanks. This product does not contain pesticides, biocides, or the toxic formaldehyde-releasing ingredient bronopol. For best results, use (1) Drop-IN every three months. Camco makes quality products for RVing, boating, camping, towing, tailgating, and grilling that help you take your passion for the outdoors to the next levelFeatures: Black Water Holding Tank Treatment: Contains a powerful enzyme complex that helps clean your holding tankKeeps Tank Sensors Functioning Efficiently: Just (1) Drop-In treats up to a 40-gallon tankSafe for All Septic Tanks: This product does not contain pesticides, biocides, or the toxic formaldehyde-releasing ingredient bronopol; Safe for all septic tanksFor best results, use one Drop-In every three monthsThe product is made in the USA*Sold as a pack of 6