From the Manufacturer

The HS-425BB is offered with dual ball bearings, impact resin gears and high performance circuitry. As one of our longest running production servos, it has proven to be a durable and dependable product year after year. Specifications Motor Type: 3 Pole Bearing Type: Dual Ball Bearing Speed (4.8V/6.0V): 0.21/0.16 sec @ 60 deg. Torque oz./in. (4.8V/6.0V): 46/57 Torque kg./cm. (4.8V/6.0V): 3.3/4.1 Size in Inches: 1.59x0.77x1.44 Size in Millimeters: 40.39x19.56x36.58 Weight ounces: 1.60 Weight grams: 45.36.