Anyone have any experience with using these new plugs?

What makes the C7TGH plugs different from the C7TGF plugs?

According to Novarossi's website, the C7TGH plugs are meant for ambient temps of only 0 to 10 deg C??

If the above is correct ,then I purchased the wrong plugs?

If anyone has used these plugs for ambient temp range between 15 to 30 deg C, I'd like to know whether they worked fine or not.

Thx!!