A wide selection of waste tank sizes ensures you the right fit for your boat or RV. All Moeller waste tanks meet the material and pressure specifications for sanitation tanks as called out in federal regulations. Each tank features a nominal wall thickness of 0.30 in (7.6 mm) to control odor which would otherwise permeate through the walls. Gals. 28 Size 23.5" L x 20" W x 15.5" H