GENERAL WIRE 2"" FLOAT MODEL FLOOD GUARD 2F FLOOD-GUARD OPERATES LIKE A CHECK VALVE TO SEAL OFF WATER BACK-UP CAUSED BY OVERLOADED SEWERS. WATER FLOWS NORMALLY THROUGH THE DRAIN UNTIL THE SEWER BEGINS TO BACKUP. THEN THE FLOOD-GUARD FLOAT RISES TO SEAL OFF THE DRAIN OPENING UNTIL THE WATER RECEDES. A SCREWDRIVER AND A COUPLE OF MINUTES ARE ALL YOU NEED TO INSTALL A FLOOD-GUARD. ONCE IN PLACE IT CAN PREVENT PROPERTY DAMAGE AND A VERY MESSY CLEAN-UP JOB. GASKETS ARE MADE OF MOLDED RUBBER AND ALL METAL PARTS ARE PLATED OR STAINLESS STEEL. FITS 2"" PIPE.