You'll need to do some research. The Progressive Industries version protects against low voltage, surges, reverse polarity, accidental 220V plug in and about everything that can go wrong with shore power. I think the ones that plug into the pedestals are only surge protectors. It's also easier for the plug-ins to grow feet and walk off. I can guarrantee that when I sell my trailer, my EMS unit goes with me.
2013 F250 XLT
I now have a Keystone Outback, but I try to help when I can.
Bitter Gun Owner