www.pmmag.com/articles/89103-proset-systems-trap-guard
ProSet Systems' Trap Guard
May 24, 2004

ProSet Systems Trap Guard inhibits the evaporation of trap seals and provides a non-mechanical physical barrier to sewer gas, raw sewage, viruses, bacteria, insects and vermin. It installs in minutes and can be purchased as a complete drain, or as a retrofit for existing pipes or in other make drains.