Leviton GFTA2-W SmartlockPro Self-Test Slim GFCI with Audible Trip Alert, 20-Amp, White For an added layer of protection, the GFCI regularly conducts an automatic internal test to confirm that it can respond to a ground fault Provides continuous ground fault protection - detects and trips on actual ground fault even when self-test is being conducted Status indicator light shows power and protection status as well as indication of line/load reversal Audible alarm sounds when the GFCI trips, providing an alert that power has been disconnected from load(s) plugged into or fed from the GFCI Patented lockout action prevents reset if GFCI is damaged and cannot respond to a ground fault