Duravane 50 CT - TAPERED BLADE; The blade on all DURAVANES® has a slight taper from base to top for unbelievable size/weight versus steering power. This allows use of a much smaller vane than usual for a specific size shaft. This design also eliminates blade flap and unwanted noise. SUCTION FIT BASE; Our base, fitting any shaft size, is specifically designed for an instant airtight surface-to-surface bond. Most cyanoacrylates (super glue) make this bond indestructible. NO PRIMER ON THE VANE; Because our blend of materials requires no primer or any other material on the base of the vane for adhesion, DURAVANES® have an unlimited shelf life. DURAVANES® have been designed and tested to outperform any other vane, (or feather) in all aspects.Style: VANE40D