RioRand Spring SM-S4303R Large Continuous Rotation 360 Degree Plastic Servo for Robot(RR-BR301) Size:56  20.5  45mm Rotation angle:360 Stall Torque :3.3Kg/cm(4.8V) : 4.8Kg/cm(6.0V) Operating Speed: 0.12sec/60 degree(4.8V) : 0.10sec/60 degree(6.0V) JR interface 360with Robot Servo 4plastic gears+1metal gear.double ball bearing.