The Eflite G90 Gyro was a fairly good little sub-micro gyro back in the day (2008) for those with smaller 250-450 size electric single rotor RC helicopters.
At a third the weight and half the cost of a Futaba GY-401 (the most popular heading hold gyro on the market back then), the little G90 gyro had a lot going for it.
The Eflite G90 Gryo could be used in either Heading Lock mode or Rate Mode. Both modes can be selected by using either the switch on the gyro or remotely on your computerized radio using the remote gyro gain function.
Gain as well could be adjusted on the Eflite G90 gyro by the small adjustment pot for those of you without a computerized radio or of course can be set remotely using the ATV values in your gyro gain menu on your computerized radio.
Since both the gain and modes are selectable on the gyro or remotely, this gyro will work with both non computerized radios and computerized ones. Thus the reason I say it's flexible.
The G90 also allowed you to switch between a fast digital output or slower analog output frame rates allowing the use of less expensive tail rotor servos that can’t handle the high frequency rate.
Of course the G90 could be paired up with a super fast digital specific tail rotor servo like the JR-3400G or 3500G that gave impressive results if your are into 3D. With both built-in drift cancellation and temperature compensation circuitry, the E-flite G90 gyro holds the tail solid throughout the entire flight.
I have seen both the Blade 400 and Trex 450 with the G-90/JR-3400G pairing fly incredible 3D and was amazed at how well the G90 locked the tail in all flight attitudes.
At only 9 grams – this was one of the lightest full function heading lock gyros on the market at the time. Perfect for small sized electrics from 250's size up 450’s. Saving weight on small electrics pays big dividends in flight time and performance.
If you are looking at saving both weight and cash on your smaller electric heli; but still wanted good performance, a solid tail lock, and the flexibility of a gyro that works with both computerized and non computerized radios, the Eflite G90 gyro is was a good contender back in the day (2008-2010).