This is the Savox SH-0253 Super Speed Micro Digital Servo.

Savox SH0253 Features:

• Over-spec refined design out performs ordinary micro size servos.
• The metal case design looks good and allows for cooler and smoother operating temps.
• Metal gears forms a solid framework for precise control and operation.
• Strict production and quality control of plastic components ensure quality construction.
• Our servos are totally green – from materials to production, these servos are environmentally friendly.
• Ideal for CCPM and Rudder on 450 class heli's and Park Flyer Airplanes.

Spec Check:

• Dimensions: 22.8x12.0x25.4mm
• Weight: 13.6g
• Speed(@4.8V sec/60): .13
• Torque(@4.8V oz-in): 25.0
• Speed(@6.0V sec/60): .09
• Torque(@6.0V oz-in): 30.6
• Gear: Metal & Plastic
• Bearing: 1BB
• Case: Aluminum
• 21 Tooth Spline