YO255B Brand: SpringRC. Model: SM4309R. Coreless motor， metal gears， double ball bearing and connector wire included. Great for R/C robots. Comes with servo arms and screws for easy installation. Operation speed: 49 R/M (4.8V); 58 R/M (6.0V). Interface: JR. Rotation angle: 360 degree. Working voltage: 4.8V-6V. Stall torque: 7.9kg/cm (4.8V)， 8.7kg/cm (6.0V). Wire length: 30cm. Package Details Weight: 77.04 g Size: 10.7*8.5*2.3 cm Package Includes 1 × SpringRC SM4309R 360 Degree Robot Servo 1 × Set of Accessories