Bi-Delta is the first vane to be reduced in size for fly broadheads. The vane center web is removed, creating a new vent with multiple attributes. Weighing less, wind drift is reduced. Front of Center balance, energy, and speed increase. Helicals that are fletched reduce drag. Bi-Delta vanes do not assume a total helical. Front and rear are straight. Photo upper left. The material Bi-Delta is rigid and durable. It can reduce drag even at high speeds. Archers who use traditional recurve or longbow bows now have the option of choosing between two options. Keep the feathered arrows Shoot Bi-Delta Rain Vanes(tm), FEATHER LIKE(tm). Bi-Delta Plains Vane (tm) for rain and snow hunting. United States National Archery Association Flight Committee legalized the Bi-Delta Vane. Harold Drake is listed in the Guinness Book of World Records as having held numerous world records. Bi-Delta Vanes were used to break the World Broadhead Flight Records. Mr. Drake’s archers broke the world record for broadhead flight by shooting carbon arrows and 125 grain 3-blade broadheads. Bi-Delta has arrow vanes for a variety of shooting situations. Release aid archers shooting mechanical heads using conventional 4" vanes would see their speed reduced through a chronograph when compared with the same arrows shot by Bi-Delta's 2.5" Shark's Tooth (tm) and 3". The 2.5" is 4.5 grams. The 2.5" can fly heads up to 100 grams. The Bi-Delta Sharks' Tooth 2.5" is a great tool for guiding 100 grain broadheads that have a low profile. Check the AVL(tm) vane models. Check out the AVL (tm). You can contact us by e-mail, phone or fax for assistance in selecting the right hunting, target and crossbow vane.