The Test-Tite® Pressure Relief Pneumatic Test Plug is a patent-pending device designed for the purpose of testing or temporary blocking of plumbing DWV systems. Manufactured with a patent-pending pressure relief valve that is integrated into a glass-filled nylon core for protection and extra rigidity in the field. The internal pressure relief device acts as a safety valve to reduce the chances of over inflation. The Pressure Relief Test Plug is designed to release excess pressure above the suggested inflation pressure, into the atmosphere rather than into the test area, thus reducing the possibility of over inflation or blowouts.