The Jackel-SF24D is a duplex cover that provides a gas and radon tight seal to any Jackel 24" diameter basins. It is constructed of injection molded polyethylene structural foam and is extremely flexible for any duplex pump installation. The Jackel-SF24D comes with 1-1/4", 1-1/2", 2" or 3" discharge flanges and 2" or 3" vent flange and a 6" access opening.