Testing products are devices designed to temporarily seal supply or drainage systems, to verify system integrity through air or water pressure testing. Test caps and plugs are installed at pipe ends or openings; inflatable test plugs are designed to expand inside the pipe to block flow and isolate sections; and gauges measure pressure during testing to confirm the system holds pressure without leaks. During testing, sections of the piping system are sealed and subjected to either air or hydrostatic (water) pressure in accordance with applicable plumbing codes. Any loss of pressure indicates a potential leak, which must be corrected before the system is placed into service.