Just ordered a Progressive Industries EMS-PT50X 50 Amp surge protector from a RV parts supplier on eBay.
This is the portable EMS unit, not just for surge protection, but protects against under/over voltage. I decided against the hardwired unit because the manual clearly states
"Do not use the EMS with an inverter generator". It will cause damage and eventual failure to the EMS when the generator switches between normal and peak load. The only way to get around it with the hardwired is to get around it literally with a bypass circuit.
eBay has a 15% off anything promo code
"PSPRINGTIME" going on today
March 20, 2018. Anything you buy is 15% off up to $50 maximum discount.
Anyway, I found a RV parts supplier on eBay selling it for $335, so I got the maximum $50 discount and paid $285 OTD with free shipping. Pretty good deal.
Oh, I did check with Progressive Industries to confirm that they're an
authorized dealer so that the
Lifetime Warranty coverage would apply. PI said that as long as the retailer provides an invoice, then the Lifetime Warranty would apply.