Radiant Spec Grade 15 or 20 Amp Tamper Resistant Self Test GFCI conducts an automatic test every three seconds, ensuring it's always ready to protect. If the device fails the test, the indicator light flashes to signal that the GFCI should be replaced. It also has our proven SafeLock Protection feature: if critical components are damaged and protection is lost, power to the receptacle is disconnected. Feed-thru wiring configuration allows GFCI to protect downstream receptacles. Prevents line-load reversal miswire: no power to the face or downstream receptacles if wired incorrectly. Feed-thru wiring configuration allows GFCI to protect downstream receptacles. High-impact-resistant thermoplastic construction. Class A rated GFCI. UL Standard. UL listed.Note: >/B> Radiant Screwless Wall Plate sold separately.