Renzetti Double Ender Midge Hair Stacker. A hair stacker is a tool used to align the tips of hair cut from a hide before attaching it to the fly. It is as simple as putting the fur to the brass tubing, insert it into the hair stacker, gently tapping a tabletop with it a few times and all the fur or deer hair tips will be even, ready for you to attach it to the fly. Renzetti manufacture many different sizes of hair stackers to suit your need. Each hair stacker has an aluminum base and 1 brass barrel. The brass barrel is smooth to allow the hair to slide easily. The alum base come with a rubber pad to protect your table. Renzetti product line is manufactured in the USA.