Extra Heavy-duty industrial and hospital grade GFCI modular receptacles. Advanced electronics offers superior resistance to surges and over-voltages. Patented lockout feature prevents reset if the GFCI is mis-wired or the circuit is no longer functioning properly. Green LED indicator light indicates the presence of power to the receptacle. Constructed with impact and chemical resistant PBT face, increasing durability to the device. Brass self-grounding clip permanently staked on for secure and reliable performance. Improved strap design provides greater support, even with ears removed. Wraparound steel strap for superior durability in abusive environments. Feed-through terminal screw covers provide added safety on unused terminals.