Surge Protector and Extension Cord

I have a Progressive Industries EMS (superior in functions to Surge Protector -- the PI unit shuts down if low voltage, a much more common problem than surges in RV parks), as well as surges. I plug mine into the pedestal. The PI units have a metal thingy on the cord with a hole for a padlock, so I use a security cable plus padlock. It could be defeated fairly easily with tools, but some deterrent is better than no deterrent!