This is a Used IPS Controllers PS100 Pressure Switch 110-220V Extra, affordable protection against accidental chemical exposure. Mechanical failures and human factors can create serious situations whereby a swimming pool circulation pump stops, but the chemical controller continues to release treatment chemicals. If the circulation pump stops, the IPS PressureSwitch shuts off the controller preventing unwanted chemical release. It?s easy to install. Include our companion PressureSwitch with every new installation of an automated chemical controller and add one to every existing system. More and more health departments are requiring extra layers of protection. PressureSwitch by IPS Controllers Goes beyond Electrical Interlock by protecting a system from loss of circulation pump prime Compatible with any automated chemical control system Adjustable minimum pressure requirement (2-11 PSIG) Simple to install, plugs into any GFCI outlet An affordable solution All components are UL Listed Comply with health departments requiring secondary safety layers This was fully functional when we removed from upgrading our system. This is in great condition!