This is an MKS HBL990 Brushless Titanium Gear High Speed Digital Tail Servo. 

Compatible Gyro's:

• Spartan DS760, Quark
• Futaba GY611, GY601, GY520
• ALIGN GP700, GP750
• Mikado V-Bar Tail, CSM SL720
• Curtis Youngblood Mini-G, Solid G
• Thunder Tiger TG-7000
• BeastX Mircobeast

Specifications:

• Torque:
• @6.0V: 65.2 oz-in (4.7 kg-cm)
• @7.4V: 80.5 oz-in (5.8 kg-cm)
• @8.2V: 87.4 oz-in (6.3 kg-cm)
• Speed:
• @6.0V: 0.04 s
• @7.4V: 0.036 s
• @8.2V: 0.030 s
• Weight: 70.55 g
• Dimension: 40x20x40mm  
• Working Voltage: 3.5 ~ 8.4 V DC Volts  (2S Lipo un-regulated)
• Working Frequency: 760μs / 560hz
• Dead Band: 0.0008 ms (Default)
• Bearing: 2BB
  
• Motor: 4-Pole Brushless Motor
• Gear: Chrome-Titanium alloy gear