The Jackel-SF24B-GR is a blank green 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 pump installation. The Jackel-SF24B-GR comes with cut outs for 1-1/4", 1-1/2", 2" or 3" discharge and 2" or 3" vent and a 6" access opening.