This is an Airtronics 94647 (ERS971) Low-Profile High-Speed Metal Gear Coreless Digital Servo. This low-profile digital servo is ideally suited for use in 1:10th scale cars. In addition to being waterproof, this servo features a coreless motor, dual ball bearings, metal gear train and an aluminum heat-sink.

This is a Hitec HS-7115TH Ultra Slim HV High Voltage Digital Titanium Gear Servo. With its efficient, powerful three pole, metal-brushed motor and mighty titanium gear train, this servo brings the ultimate in high performance to your sailplanes, pylon racers and smaller scale models.

This is a Savox SC-1251MG Low Profile High Speed Metal Gear Coreless Digital Servo. This servo features metal gears and a coreless motor.