Part Number: ST3215- 7.4V Servo ST3215 Series Serial Bus Servo, High Precision and Torque, with Programmable 360 Degrees Magnetic Encoder, Two-Way Feedback, Servo/Motor Mode Switchable, 19.5 kg. cm@ 7.4V Torque Servos will provide various feedback like position, speed, torque lock, operating mode (servo mode, servo motor mode, etc. ) for advanced projects requiring closed-loop automatic control. Ideal choice for building quadruped robots, hexapod walkers, robotic arms and other robotic projects requiring multiple servos. (This product provides the open source model of the quadruped robots as shown in the picture below. ) UART Serial Bus Control allows controlling up to 253 serial bus servos at the same time Up To 30kg. Cm Torque On 12V version, Suitable For Building Quadruped Robots, Hexapod Walkers, and Robotic Arms Up To 19.5 kg. Cm Torque On 7.4V version, offering stable and efficient performance in small-to-medium robotics projects. Users can flexibly select options based on their specific requirements.