Futaba GY401 Head Locked Gyro for 400 450 RC Helicopter Remote Control Toys Parts Type: Micro Heading Hold Gyro . Sensor: SSM AVCS . Weight: 27g . Dimensions (WxLxH): 27 x 27 x 20mm . Gain Setting: Remote Only . Mode Setting: Rate or Heading Hold  Remote Only . Operating Voltage: 4.8 VDC (Needs a voltage regulator (6 VDC) if using higher than 4.8v battery packs) . Reversing Switch: Yes, on gyro . Limit Trimmer: Yes, adjustment on gyro . Function: with reverse switch, DS mode switch, control delay adjustment knob, servo stroke volume adjustment knob. By transmitter to adjust gyro sensitivity and switching lock (AVCS) mode and normal mode. . Futaba GY401 Features: AVCS (Angular Vector Control System) is Futabas patented heading hold gyro technology. AVCS works better than other HH . gyro systems at correctly compensating for and eliminating drifting issues in heading lock/hold mode caused by . temperature changes within the gyro. . The GY-401, just like all of Futabas AVCS gyros uses a SMM gyro sensor and is said to be better than other conventional . solid state yaw sensing technologies since all the electronic components are combined on a single chip improving . performance and reliability. SMM stands for Silicone Micro Machine. . Both Gain and Heading Lock/Rate modes are remotely adjustable through the gyro settings menu on a computerized radio. If . you dont have a programmable computerized radio that you can program in different ATV values for the gain settings, the . Futaba GY401 will not work for you  there are no gain or mode selection options on the gyro case. A better choice for . Package Includes: 1 x Futaba GY401 Head Locked Gyro .