Radient RS-BS201-PG Standard 5kg Analogue BB Servo RC Spare. Key Features: O-ring seals. Water resistant. 3P iron core motor. 25 tooth spline. Dual ball raced output shaft. Product Description: Offering the size, power, torque and speed to suit a variety of applications Radient servos are rapidly building a reputation for reliability that compliments their outstanding value. This dual ball raced, water resistant, 5kg 'standard' unit is no exception.