In a previous informative thread it was mentioned that many surge protectors require a ground to work. Are there any types that can be used on ungrounded (GFCI) outlets?
PC
The really cheap and basic ones only provide protection between hot and neutral, so absence of a ground will not affect their operation.
Better protectors will also add hot to ground and neutral to ground protection. These will be no more effective in an ungrounded outlet as the cheap ones.
From the other thread
Are there any quality ones that protect well with an ungounded outlet?
Nope. Without a ground, the “extra” supressor components (hot to ground and neutral to ground) are useless.