MG958 is best choice if you need higher torque than 15KG.And Std Size
Excellent performace for Our 6X6 And 8X8 Trucks Where High Torque Is Required For 4 Wheel Steering Etc.

Specification:

Weight: 65g
Dimensions: 40.2 x 20.1 x 36.8mm
Operating Voltage: 4.8v-6.6v
Stall Torque (4.8v): 18.0kg.cm
Stall Torque (6.6v): 20.0kg.cm
Servo case: Alloy case in the middle
Gear Type: Metal gear
Bearing: Double ball bearing
Temperature range: 0- 55deg
Operating Temperature Range: -20 ~ +60 Degree C
Operating Speed (4.8v): 0.18sec/60 degree
Operating Speed (6.0v): 0.15sec/60 degree
servo wire length: 32cm
Servo Plug: JR (Fits JR and Futaba)
servo arms &screws included and fit with Futaba servo arm
CE &RoHS approved

We have upgraded our servo gear set and shaft to aluminum 6061-T6.
It is stronger and lighter than copper.