Designed to meet the latest UL standard for auto-monitoring (self-test) this complete line of self-test of this 15-Amp GFCI Outlet periodically conduct an automatic internal test to confirm that it can respond to a ground fault. With the slimmest profile on the market, the device allows for fast and easy installation, while the patented reset lockout mechanism prevents reset of the GFCI if it is not wired or operating correctly.