Under the Ham-O top layer is 8-layer polypropylene construction

which must be purchased separately as they are not included from the manufacturer

ASTM D2859 (CPSC FF 1-70)

synthetic detergents and antibacterial soaps that contain either PCMX or Triclosan

the seat is covered with sponge padding and off-white naugahyde

BOB Pipe-Mount Float Valve, 3/8 in -16 Rod Thread, Stainless Steel w/Viton Seal - R1380-2 Capacity-57 oz Under the Ham-O top layerFeaturing heavy duty stainless steel construction for corrosion resistance, this BOB high capacity float valve is ideal for use with caustic fluids and where sanitation is a concern. The valves short arm design allows you to easily adjust the water level to meet your specific requirements. Durable seals help provide long life.