What are the most effective forearms exercises to gain mass in the encercled areas (see pic)?

Reverse barbell curls.

The pump alone is so intense my hands shake like crazy. Gained some juicy gains.

dumbbell wrist curls and a gripper

Dumbell arm fliparound barbell press curl. It made my forearms pop so try that

It's just that i've seen a lot of people with big muscles near their elbow but not so much near their wrists (and NO i'm not talking about tendons, but a little higher in the forearms)

And I've seen other people with a forearms FULL of muscles, from near the wrists (again, I know there are no muscles in the wrists) to near the elbows.

And I just want to not make the mistake of only training a part of my forearms by neglecting some muscles near the wrists. BUT if it's just genetics then I didn't know about it and ok, I'll see how it'll goes with me.

Genetics.

most people I've seen with forearms legit FULL of muscles as you said are grapplers

they probably (along with physical workers, stonemasons and such) have the best and most hardcore forearm training sans armwrestlers

Thanks

Climbers have great forearms

your forearms are made of muscles that go all the way the lenght of it from shoulder to wrist so yeah it's genetics

reverse curls