Do Implicit abilities stack or work with gem abilities

I have an Alpha's Howl with an implicit ability of "Grants level 11 Hatred Skill". Does this ability stack with my hatred gem, if it does does, does it stack as a single hatred buff with double the amount, or is it a separate hatred buff?

Edit: If I take the helmet off my dps does not change, is this implicit like having the gem aura on as a lvl 11 gem, if so why does my dps not change. I took off my hatred gem during this test

Edit: I just figured it out. It put a hatred buff in my skill box to put on a key, it does not stack.
Thanks for any help!

Pretty sure the highest level one will be used. Just mouse over your dps with and without your own aura running.

it works the same as having lvl 11 hatred socketed in alphas