Quadplex duct plugs are split plugs for sealing around, organizing, and supporting up to three subducts, pipes, or cables. These plugs are designed for use in round openings such as conduits, conduit fittings, and core-drilled wall penetrations. Effective, long-term watertight and air-tight seals, prevent mud, backfill, and slurry from entering handholes, manholes, and buildings during the construction process.