Amazon.com : PESTPLUG - 100% Stainless Steel Wool, Large DIY KIT, Rodent Barrier/Fill Fabric - Use to Block Mice, Rodents and Flying Insects. Does NOT Rust! Plug or Fill Holes, Cracks and
McAlpine 4 inch/110 Millimetre Anti Back-Flow and Rodent Barrier Valve by McAlpine Plumbing Products