This is a EcoPower Aluminum Clamping Servo Horn (25T)

This is an optional EcoPower Aluminum Clamping Servo Horn, intended for use with EcoPower servos along with other 25T splined servos. This extremely tough servo-horn has been machined from a solid block of aluminum for incredible precision, rigidity, and durability. The horn features a clamp type design that grips the servo’s output shaft so if the retainer screw comes loose, the horn will have a better chance of remaining in place, increasing your chances of finishing the race! 

Features:

• Clamping design
• 16.5mm and 20mm hole spacing (measured from output shaft screw hole, to linkage rod holes, center to center)
• Dimensions (LxWxH): 30x9x7mm
  
• 3.5mm thick arm
• 25T Spline EcoPower Output Shaft
• Linkage holes threaded for 3mm hardware