This is the round servo horn that comes with the Futaba S34, S134 & S134G servos. Also fits S28, S29, S30, S31, S32, S38 & S48 servos and their 'J' style counterparts. It is a splined servo horn with a diameter of 1 3/4" and includes a mounting screw. NMH 3-26-92  

BOX DIMENSIONS: 2.38" W. X .25" H. X 2.38" L. BOX WEIGHT: .02 LBS.