These are the perfect foam slot fly boxes to divide your flies into visible categories and stack a bunch of boxes in a small space. They are very light so they don't add a bunch of weight to your pack that is likely already there from tungsten beads. The small box makes a great working box for the day or a competition.
The small box holds 104 flies in its 5"x 4"x 0.5" frame.
The long box holds 164 flies in its 7.25" x 4" x 0.5" frame.