This is the HS-645MG Metal-Geared, Coreless, Ball Bearing, Hi-Torque Servo from Hitec. This version of the servo has a universal connector which will fit Airtronics, JR, Hitec and Futaba receivers (be careful with the polarity of the connector for Futaba radios).

Specifications:

• Speed:
• 4.8V: 0.24 sec/60 deg.
• 6.0V: 0.2 sec/60 deg.
• Torque:
• 4.8V: 107 oz/in
• 6.0V: 133 oz/in
• Length: 1.5in (38mm)
• Width: 0.79in (20mm)
• Height: 1.61in (41mm)
• Weight: 1.95oz (55.2g)