This is a Hitec Super Torque, Metal Gear, that will work with Futaba J, Hitec S, JR, and Airtronics-Z radio systems. FEATURES: EPA, Speed, Direction, and Fail-Safe Programmable (see COMMENTS). MOSFET amplifier. Gold plated contacts. Three metal gears Dual ball bearings. Indirect drive long life potentiometer. High standing torque. Watertight and dustproof. Includes blue aluminum, heat-treated servo arm (see COMMENTS). Works with fixed wing aircraft and helicopters up to 40 pounds, 1/10th and 1/8th on- or off-road vehicles. INCLUDES: One digital high torque servo with 12" wire and S/JR/Air-Z connector One white small X-shaped servo horn. One red Large X-shaped servo horn. One white adjustable servo horn. One white offset straight servo horn. One white disc servo horn. One blue anodized, heat treated servo arm horn. Four 2 x 14mm mounting screws Four brass eyelets Four black rubber vibration isolators. REQUIRES: Futaba J Hitec, JR, or Airtronics-Z radio system SPECS: Speed: 0.23 sec/60° at 4.8V Speed: 0.18 sec/60° at 6.0V Torque: 143.03 oz-in at 4.8V Torque: 164.2 oz-in at 6V Length: 1.59" (40.6mm) Width: 0.77" (19.8mm) Height: 1.48" (37.8mm) Weight: 2.11oz (60g) COMMENTS: Programming the Fail-Safe: In order to program the Fail-Safe on this servo. Modeler will need to purchase the Hitec Field Programmer. The metal servo horn will fit any Hitec servos that have a "+" stamped on top of the output shaft.