The Knaack PowerCrew 15-amp in-box power supply provides a safe and powerful power source on or off the job. Four GCFI-protected electrical outlets provide power for operating tools or recharging batteries, and a standard-three-prong blade extension cord plugs into the outside of the box. Safety features include an internal relay that senses broken wires in the power supply line, remaining open to prevent electricity from reaching operators. A red LED light indicates the four outlets have power and are ready for use.