Professional Electrician Grade 15AMP GFCI. Meets National Electric Codes for new construction. The Professionals Electrician's Choice. Fast Connect Terminals. Ground Fault Circuit Interrupter. Monochromatic Test Buttons. Istalls in all standard electrical boxes. Residential Grade 15A-125V 20A feed through. Installation and testing instructions included. WARNING: use this device with Copper or Copper Clad Wire only. Do not connect to aluminum wire.