This is the Hitec D840WP Programmable Mega Scale Waterproof Servo. Ideal for airplane, giant scale car, boat, UAV and robotic applications Center heat sink for efficient motor cooling Operates on 3.5-8.4V Programmable high response digital amplifier* Durable steel gears with dual ball bearings Water and dust resistance D840WP Servo with 1.6" (39.9mm) Round Servo Horn, 1.8" (46mm) Single Arm, 2.2" (55mm) Double Arm Aluminum Horn. 2.4" (61mm) 4-Point Horn Four each, Grommets, Eyelets and Screws 3mm Servo Horn Screw 2.59 x 1.26 x 2.44" (66 x 32 x 62mm) Weight: 8.0oz (227g) Output Spline: 25 tooth 4.8V 6.0V 7.4V Speed: 0.17 sec/60° 0.14 sec/60° 0.11 sec/60° Torque: 264oz-in (19kg-cm) 333oz-in (24kg-cm) 417oz-in (30kg-cm) *Programmble features require the Hitec DPC-11 Universal Programming Interface, HRCP4429 jxs 03/18/16 ir/jxs &