Plugtail Registered Hospital-Grade 20A Self-Test Gfci Receptacle. Self-Test Gfci Technology - Conducts An Automatic Test Every Three Seconds, Ensuring It'S Always Ready to Protect. Plugtail Registered Devices and Connectors Mean That Device Installation Is The Same Regardless Of Skill Level Of The Installer. The Ul-Listed Connectors Are Keyed to Ensure Proper Wiring Installation Into Each Receptacle.