unit turns any standard 120v receptacle into a GFCI (Ground Fault
Circuit Interrupter). This is the same style of outlet that is
found in your kitchen or bathroom. It helps alleviate some of the
issues with electricity and damp locations by sensing if there is any
current leaking to the ground (possibly through you) and shutting off
the current flow. You do not need to plug the Blasting System
into one of these but it is advisable to use one when drilling in
damp locations. This unit has an output of three receptacles.