Spring RC SM-S4209M 2BB Metal Gear High Speed Digital Servo Torque: 4.8V: (120.82oz/in ) | 6.0V: (133.32oz/in) Speed: 0.13sec (4.8V) | 0.11(6.0V) Operating Voltage: 4.8 - 6.0V Weight: 62g (2.19oz) Dimensions: 1.63 in (41.3mm) x 0.81 in (20.7mm) x 1.57 in (40mm)