This is the JR Sport MC35 Micro Servo.  This is great for many electric and small glow planes.  It has a universal connector that works with JR, Hitec, Futaba, and Airtronics.

Specifications:
Size Category: Micro
Type: Analog
Torque: 35 oz/in @ 6.0V
Speed: .21/60 @ 4.8v, .17/60 @ 6v
Dimensions (WxLxH): 0.50 x 1.12 x 1.17
Weight: 17.0 g (0.6 oz)
Bushing Or Bearing: Bushing
Gear Type: Nylon
Application: Small engines, Electric powered