This is the Futaba GY401 Gyro with an S9257 Digital Servo.
This is a high performance, compact and lightweight (AVCS) Angular Vector Control System gyro developed for model helicopters.
The sensor and control circuit are integrated, it is simple to install.

Features:

AVCS System: Since the rudder trim changes (caused by wind and other meteorological changes) the front, rear, and other heli lttitudes

SMM Gyro Sensor: Use of this newly developed technology virtually eliminates rudder trim changes during fligh.
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.
Included high-speed S9257 Digital Servo boasts 27.76oz-in torque and a speed of .08 sec/60?#60;BR> 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.

Specifications:

GY401 Gyro:
Length: 1.1"?(27mm)
Width:?1.1"?(27mm)
Height: .79"? (20mm)
Weight: .95oz (27g)
Torque: 47 oz-in
Speed: .06 sec/60?#60;/p>

S9257 Digital Servo:
SPECS:  ?Length: 1.40" (35.5mm)
Width:   .59"   (15mm)
Height: 1.13" (28.6mm)
Weight:?.9oz (26g)
Torque: 27.76 oz-in (2 kg-cm) at 4.8V
Operating Speed:?.08 sec/60?at 4.8V
Cord Length: 7.9" (200mm)