GY-401

This is the GY401 Gyro with SMM Technology from Futaba. This is a High Performance, Compact and Lightweight (AVCS) Angular Vector Control System gyro developed for model helicopters. Because the sensor and control circuit are integrated, it is simple to install.
Feature

SMM Gyro Sensor: Use of this newly developed technology virtually eliminates rudder trim changes during flight (see COMMENTS).

Digital Servo Compatible (DS Mode): DS mode makes it compatible with Futaba digital servos.
This 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 design made possible by high density mounting technology. Conductive Resin Case: This case improves EMC (Electrostatic and electromagnetic interference) resistance.
Voltage- use only with a 4.8V battery.
(if you use it with a higher voltage battery it needs to be regulated to 6V)

AVCS System: Since the rudder trim changes (caused by wind and other meteorological changes).
The front, rear, and other heli attitudes change and are automatically cancelled. Tail (rudder) operation is easy, making it perfect for 3D flight.
(also known as Heading Hold Gyro)