This is the Savox SB-2231SG Ultra Torque, High Speed, Brushless, Tall Size, & Steel Gear Digital Servo.

Savox SB2231SG Features:

• Combines leading edge technology with super high 12 bit (4096) resolution and unique steel gears.
• Brushless motor provides longer life and cooler operating temps.
• Extremely strong unique steel gears ensure long-life and durability.
• The aluminum case design not only looks good but also allows for cooler and smoother operating temps.
• Our servos are totally green – from materials to production, these servos are environmentally friendly.
• Ideal for giantscale aircraft, monster truck, rock crawlers, and 1/8 scale.

Spec Check:

• Dimensions(mm): 40.3x20.2x45.0
• Weight(g): 84.0
• Speed(@6.0V sec/60): .14
• Torque(@6.0V oz-in): 444.4
• Speed(@7.4V sec/60): .10
• Torque(@7.4V oz-in): 555.5
• Gear: Unique Steel
• Bearing: 2BB
• Case: Full Aluminum
• 25 Tooth Spline
• Frequency: 250-333hz
• Pulse Width Frequency: 1520