Howling Harpoon question -
 

Probably a stupid question - but does anyone know - is the Howling Harpoon 'stun' a random proc that only works if equipped as a primary weapon, or is it clicky, and can that be used if it is in the ranged slot? It starts working at 40, and my Shaman is close, want to know a little more about it so I can make some decisions about what to equip where, and maybe not find out the hard way in battle lol.

Proc from primary melee only.

Ah - thanks!