Bryant Electric GFBFST20GY 20 Amp 125V Commercial/Residential Self Test Faceless GFCI Receptacle, Gray Patented circuitpro technology, device continuously self test's functionality and disconnects power to the receptacle if critical components are damaged and gfci protection is lost Clear visual indication of gfci status, ground fault end-of-life indicator included, flashing red led indicates device has lost capability to provide protection, green led indicates power to the device and solid red led indicates the device has tripped Protection against line and load reversal, for safety reasons, no power is provided to the receptacle face or downstream receptacles if the device is wired incorrectly Installation ease, lower installation time, receptacles are easy to install with internal back wiring, captive mounting screws, and an automatic self-grounding clip Ul 943 gfci safety standard, Bryant's latest generation of diagnostic technology exceeds the 2015 ul 943 gfci standard revisions