Meets new UL requirements issued in 2008. UL Standard 943 Class A(GFCI) and 498(Receptacle) 2-pole,3-wire grounding duplex receptacle Impact-resistant thermoplastic cover and body More resistance to electrical noise and to moisture corrosion Press interval (monthly)test button, then press reset button in order to confirm the GFCI works properly, if reset state fails, the working LED will turn off, GFCI life expired and need to be replaced by a new one. End-of ¨Clife indication LED will turn red immediately if GFCI has lost its ability to protect, then pressing the test button to use the function of Manual compulsory to trip, and it will not reset anymore that may prevent personal injury or death due to a ground fault. GFCI with Tamper Resistant, It may stop the kids use any foreign body to connect the receptacles any alive parts from the outlets. Reverse miswiring will not be reset and the green indicator led will be lighting Manual compulsory trip under some emergent cases when GFCI is in a fault working state, it is the most advanced Technology and safest fault current interrupter in the world so far, which make good of the defect of GFCI to trip only under the condition of power feed through. The most advanced protection device, having the special functions of mechanical compulsory trip and without any consume According to the customer's request