Thetford's Level Gauge Cleaner is specially formulated to dissolve tissue waste sludge and soap scum build-up. The 100% biodegradable liquid works with both black and grey water tanks, on RVs or boats. The Level Gauge Cleaner prevents build-ups and restores level sensor operation fast. Highlights: VERSATILITY: Thetford's Level Gauge Cleaner is designed to work with RVs and boats FUNCTIONALITY: Dissolves tissue sludge and soap scum build-ups, restoring level sensor operation fast UTILITY: Prevents build-ups on probe and tanks, when used regularly CONVENIENCE Formulated to work with grey or black water tanks SAFETY: Level Gauge Cleaner is 100% biodegradable.