The Crossbow Tower is a fletching system that accommodates .2985 and .303 shaft size arrows and allows you to fletch 3 vanes at once precisely 120 apart, and reduces your fletching time to a third! Includes the crossbow center post and two collar rings. The Crossbow Tower includes clamp release tape and 2 sets of arms: black for a 3 helical and red for a 2 right offset. The maximum vane size for fletching is 2.25" for Helical, and 4" for Offset. The Tower is not for use with swedged end shafts or feathers. The Tower saves time, increases arrow production and provides the easiest and most precise vane placement!