A quality analog 25g servo for helis and planes up to .40 size. Excellent accuracy and great centering.

You wont find a better quality servo at anything close to this price.

Spec.
Type: Ball bearing
Gear: Plastic

Speed @ 4.8V: 0.10 sec/60 degree
Speed @ 6.0V: 0.08 sec/60 degree
Torque @ 4.8V: 2.0 kg-cm 
Torque @ 6.0V: 2.3 kg-cm
Size: 35.5 x 15 X 28.6mm 
Weight: 25g