Goteck GS-9257MG Plastic Gear 450 Electric Digital Servo Goteck GS-D9257 Digital Tail Rudder Plastic Servo for Align Trex 450 500 RC Helicopter Feature: 1520¦Ìs wide band Coreless motor Double ball bearing Perfect T-Rex tail servo High performance-price High torque¡¢High speed¡¢Hi resolution The materials use the same as international famous brand. Specifications: Dimension: 35.5mm * 15.0 * 28.6mm Stall torque(4.8v): 3.8 kg-cm Stall torque(6v): 4.2 kg-cm Operating speed(4.8v): 0.08sec/60¡ã Operating speed(6v): 0.07sec/60¡ã Operating voltage: 4.8v-6v For use with the Futaba GY401 (FUTM0807, FUTM0808) and the GY502 gyros. Equipped with two ball bearings.Comes with a selection of servo arms/discs, mounting screws. Package size: 9 * 5 * 2cm / 3.5 * 2 * 0.8in Package weight: 33g / 1.2oz Package list: 1 * Goteck GS-D9257 Digital Tail Rudder Plastic Servo