I confess I am not a graphene fabric expert, but this smells a bit. Especially the built in heater via a power pack that has 3 temperature settings - 40C, 50C, 60C.
There is a lot of BS on that page, but the temperature thing is legit. They are simply using a battery pack to heat the jacket. You can find many electric heated jackets out
there.
"Gamma is equipped with 3 carbon fiber heating elements built directly into the jacket. When your body heat isn’t enough, you can supercharge Gamma’s graphene layer at the push of a button."