The GY401 is a high performance, compact, light weight AVCS (Angular Vector Control System) gyro developed for model helicopters. Because the sensor and control circuit are integrated, it is simple to install.
Applicable servos:
Gyro performance largely depends on the servo used. The higher the speed and response of the servo, the better the gyro sensitivity and performance. From this standpoint, a digital servo is perfect for use with this gyro. The 59253 high speed digital servo developed especially for gyro use is recommended.


FEATURES
-AVCS system
Since rudder trim changes caused by wind and other meteorological changes and front, rear, forward, reverse, and other helicopter attitude changes are automatically cancelled, tail (rudder) operation is easy, making it perfect for 3D flight.
-SMM gyro sensor
Use of newly developed extremely low drift SM. (Silicon Micro Machine) gyro sensor virtually eliminates rudder trim changes during flight.
-Digital servo compatible (DS mode)
DS mode makes it compatible with Futaba digital servos. Maximizes the high
- speed response performance of the digital servo.
-Remote gain function and mode switching function
Remote gain function allows sensitivity switching from the transmitter and mode switching function allows AVCS/normal gyro mode switching.
-Integrated, compact, and lightweight
Compact size (27x27x20mm) and light weight (27g) realized by high density mounting technology.
-Conductive resin case
Conductive resin case improves EMC (electrostatic and electromagnetic interference) resistance.

This GY401 comes with Futaba FPS9253 with the following specification:

S9253 Digital servo for Gyro Rating:
Speed: 0.08sec/60 degree at 4.8V
Torque: 2.0kg-cm at 4.8V
Dimensions: 40x20x36.6mm
Weight: 49g