The Original Radon/Sump Dome manufactured by Jackel Inc. (Model SMR16101-CV). This sump pit lid is designed to fit over an existing sump pit, mounted directly to concrete, so it is suitable for retrofits or new installations. It provides a heavy duty cover while retaining a clear view port and removable lid for serviceability. Creating an air-tight seal, the SMR16101-CV prevents bugs and gases (radon, sewer, etc) from coming into your living space. The lid provides passive radon mitigation (sealing) but is also fitted with provisions to facilitate installation of a sub-slab depressurization radon mitigation system.
SMR16101-CV is made of Polyethylene Structural Foam , with an outer diameter of 28″ and inner diameter of 24″. Additional details and specs can be found at: https://www.jackelinc.com/smr16101-cv.html