It's textured surfacce allows the vanes to steer the arrow more efficiently, improving speed. The concave base has an applied activator to improve adhesion and arrow assembly.Tough material with great instant adhesion! World's best quality and colors Glue activating base Bright, visible colors Excellent memory & durability Available in: Five Sizes: 16, 23, 26, 40, or 50 Ten Colors: Black, Blue, Bright Green, Fire Orange, Hot Pink, Purple, Red, Sunset Gold, White, or Yellow. Count Size: 100 pk/Fletching only or 50 pk/Fletching with 3 gm Tube of Fastset Gel. Elite Plastifletch Vanes SIZE LENGTH HEIGHT GRAIN WT. EP-16 1 3/4" .38 3.2 EP-23 2 3/8" .38 4.9 EP-26 2 7/8" .500 7.2