hunter bow set?

how to get the hunter arrows for the hunter bow to make more damage?Cant find any infos  or quest about it.Anyone knows?When you right klick on the hunter bow you can read at the end something like Set if you have the hunter bow and the hunter arrows.But how to get the arrows?

Edited by FireMcCoy, 30 June 2017 - 04:46 AM.

The arrows aren't available, they came out at a much later patch.