Piston Rod Assembly with O-RingRaritan's Piston Rod Assembly includes the O-Ring and is made specifically for Raritan's PHII and PHEII.Raritan manufactures equipment for pleasure boats throughout the world. Products include marine toilets, waste treatment systems, icemakers and water heaters. Committed to the environment and preserving sea life, Raritan designs products to help maintain an environmental balance and ensure the quality of marine waters.