Our 3.6 amp dual USB charger, 20 amp duplex tamper resistant receptacle features a smart chip that recognizes and optimizes the charging power of your electronic devices for fast and efficient charging of tablets, phones, gaming devices, e-readers and a host of other electronic ...Our 3.6 amp dual USB charger, 20 amp duplex tamper resistant receptacle features a smart chip that recognizes and optimizes the charging power of your electronic devices for fast and efficient charging of tablets, phones, gaming devices, e-readers and a host of other electronic devices. reaches up to 87% energy efficiency according to DOE and CEC lab testing, which is higher than the average testing result of most similar products in the market.