Futaba S9157 Digital Hi-Torque Servo FEATURES: Ideal for large competition airplanes Coreless motor Dual ball bearings and metal gears Metal middle case helps dissipate heat INCLUDES: Futaba S9157 High Torque Servo with 0.83 diameter round horn, 1.8 diameter round horn, 1.2 6 point horn REQUIRES: Installing in model, connecting linkage and connecting to receiver