Futaba Single Thin Aluminum Horn Red 20mm.Add style and strength to your model with Aluminum Servo horns from Futaba.FEATURES:Sturdy aluminum construction (red in color)Single sided arm with 4 pre-drilled starter holesSplined mounting hole for easy repositioningDesigned to fit Futaba standard size servos with approx. 6mm output shaft.Many larger (1/4 scale) servos have approx. 7-1/2mm shaft.INCLUDES:One 20mm (.78") long red aluminum servo hornSPECS:Length: 20mm (.78") (from center of mounting hole to center of first starter hole)Thickness: .083" (2.10mm)Diameter of the four starter holes: .078" (2mm)