IBS Sand Bag Top BlockThe IBS top uses the late model Farley sand bags to make the Rodzilla 5 Axis top legal for benchrest competition. Remove either end by pushing out a dowel pin and slide your sandbag in and replace the adjustable end. We maintain a snug fit with the sides of the bag by providing a slot for the slightly wider base of the bag to slide into instead of pushing down from the top. Edgewood and ProtecTormodel makes a one piece bag in 3 widths. Edqewood also