These keyless lock boxes are made of heavy-duty, 20-guage, white powder-coated galvanized steel to help resist rust and dents. Boxes are insulated to protect specimen integrity and fully gasketed to maintain a water-tight seal. Each box is equipped with an over-the-door metal strap to securely fasten to structure and attached door chain to help prevent samples from falling out of the container. Fits doors up to 1¾ in. thick.