Hair stackers are an essential tool for any fly tyer. I use mine for both steelhead and trout patterns. When tying a fly with a hair wing, first you cut the hair off the hide, comb out or use your fingers to remove all the fine fluffy underfur, then drop the hair tips down into the stacker. A couple of stout taps of the stacker on the table will ensure that all the tips are evenly standing on end in the stacker. Then you hold the stacker parallel to your desk and slowly remove the inner tube. The neatly stacked tips of hair will be hanging out of the end of the tube. You will easily be able to pinch the fibers to keep them neat as you apply them to your fly.
Use the big stacker for steelhead flies like Lum Plums, Steelhead Coachmen, etc. Use the small stacker for elk hair caddis and other small trout flies.
These stackers are aluminum.