Universal Marine Boating Brand accessories Heads Up™ 1 qt. Holding Tank Odor Protector (MK4532) by MaryKate®. 1 Piece. Works instantly to control odors. Long lasting pleasant fragrance. Helps keep holding tanks and recirculating and portable toilets clean and breaks down waste and tissue. Non-formaldehyde formula. The longevity of your boat and the way it looks depend on the quality of the products you use for its maintenance. Only the finest products will allow you to achieve desired results without putting a strain on your neck and back. Made from high-grade materials utilizing state-of-the-art machinery, this product is exactly the one you need to keep your boat in mint condition year in year out.