Description:    Equipped with a brushless motor that lasts longer and operates smoother and faster than brushed motors with a greater resistance to jolts and vibration Same power consumption as brushed digital servos Dual ball bearings. INCLUDES: BLS156HV Servo with 0.83" (21mm) diameter round horn, 1.8" (45mm) diameter round horn, 1.5" (39mm) diameter four-point horn, 1.2" (32mm) diameter six-point horn, instructions and mounting hardware REQUIRES: Installing in model and connecting linkage. Specs and Features Speed: 0.15 sec/60 degree at 6.0V ,0.12 sec/60 degree at 7.4V Torque: 250oz/in (18.0kg/cm) at 6.0V ,291.7oz/in (21.0kg/cm) at 7.4V Size: 1.57 x 0.79 x 1.45" (40 x 20 x 36.8mm) Weight: 2.33oz (66g) Power Supply: DC 6.0 - 7.4V Horn Screw Size: 3x8mm