RCX MG-90S is a great servos for the price. It is a high torque, metal geared ball raced servo. This servo is similar in size to the highly popular HS65 servo. This larger servo has certain benefits over smaller metal geared servo especially in a 3D environment. The gear train is physically larger and therefore has larger teeth to mesh resulting in a stronger servo that can take some punishment. This servo is ideal for the larger EPP designs and 30 size electric models.

It is a great servo especially for swashplate but also suitable to be used as a Tail Locking Servo for 250 / 450 size helicopter. Its Speed  is not as fast as the other expensive digital servos but it is a good one to be a Tail Servo for Junior & Intermediate who do not play 3D.

• Light weight high strength nylon casing
  
• Durable partially metal gear with one bearing
  
• Recommended for 200-450 size helicopters or light weight aircraft
  
• Different servo horns included for different application

• Dimensions: 22.8 x 12.2 x 28.5mm
  
• Operating Speed (4.8V no load): 0.1sec / 60 degrees
  
• Operating Speed (6V no load): 0.08sec / 60 degrees
  
• Stall Torque (4.8V): 1.8 kg / cm
  
• Stall Torque (6V): 2.2 kg / cm
  
• Temperature Range: -30 to +60 Degree C
  
• Dead Band Width: 5usec
  
• Operating Voltage: 4.8 - 6.0 Volts
  
• Weight: 13.4g

• 1 x RCX MG-90S Standard Metal Gear Analog Servo (9g / 2.2kg / 0.08sec)
  
• 1 x Set of Servo Arm