Elevator root fairings for RV 6/7/8 - 1.6 knot IncreaseSimply put, they improve the airflow around the inboard ends of the elevators= more speed. Flight test data shows that the result is a decrease in drag that accounts for approximately a 1. 6 knot (1. 8 MPH) increase in top speed. They also close out the elevator roots for an overall tidier appearance for the airplane. They fit the following aircraft: RV 6 RV 7 RV 8 F1 Rocket and similar with RV 8 elevators They do not fit RV 4, RVs 9 through 15, or