I have not used that particuliar arm, but from the pix I have seen i would have to agree w/pm69442 , the only leveling adjustment i see on the arm is for horizontal, the bracket doesn't look like it has any vertical adjust for the arm, so while you may be leveled one way ,when you move the arm side to side it will be off if you're on a less than perfect tree..........A ball head would take care of this problem quite easily.