Hughes Autoformers RSP-50-PWD Replacement Surge Protection Module is designed for use with the PWD50 50 Amp Bluetooth Surge Protector. It features 4,800 Joules of advanced surge protection and is simple to install - only a Phillips screw driver is needed. No soldering. Make sure to unplug the unit before installing the module. Note: This module is NOT for use with the EPO unit.