The Spindrifter bottom drain is known worldwide for its quality and design. This unit completely replaces the "Standard Bottom Drain" The most noticeable feature is the extra connection in the sump of the drain. This allows the air supply hose to enter the  sump independently of the water outlet pipe, thus eliminating the possibility of restriction to the water flow and somewhere else for blanket weed to attach. The membrane and backing plate fit into a recess in the specially manufactured dome (provided). The recess in the dome prevents the membrane from becoming detached. The complete assembly is secured to the bottom drain by means of stem, which also provides the air inlet. Most water pipe sizes can be accommodated, the customer to specify. The air inlet is via a nickel plated connector.