To avoid delays, please remember to include the fin tang width* in the "Tang Width" box when ordering A thru D style fins.
*The fin tang is the shaded area shown in the drawings. It is the part of the fin that extends into the airframe through the slot and contacts the motor tube.
You can either enter in the actual width in inches
or you can state which airframe and motor mount tube you will be using
(i.e. QT-3.9 - PT-1.5)
and we'll do the calcs for you!
If you are surface mounting these fins, please enter ZERO for the fin tang width.