RioRand 4 x MG90S Metal Geared Micro Servo For Plane Helicopter Boat Car New Product size: 22.8 * 12.2 * 28.5mm Working torque: 2KG/cm Reaction speed: 0.11 seconds / 60 degrees (4.8V) Structural Material: Aluminum metal teeth, coreless motor, double ball bearin 4 xMG90S Aluminum Metal Gear Servo