We have 2 units of the Analog Feedback Micro Servo - Metal Gear in stock at our Sydney warehouse.
Analog Feedback Micro Servo - Metal Gear
We can get a further 100 units from Adafruit Australia.
If you order today we can dispatch this stock between Friday, Mar 29 and Wednesday, Apr 03 2019.
Adafruit's Description of the Analog Feedback Micro Servo - Metal Gear
It looks like a micro servo, it acts like a micro servo, but it's more than just a micro servo! We got a factory to custom-make these quality metal-geared 'micro' sized hobby servos with a twist - the feedback (potentiometer wiper) line is brought out to a fourth white wire. You can read this wire with an analog input such as those on an Arduino, to get the servo's position. That information can be used in robotics to improve stability or even allow 'recording' of servo motion.
Note that the default servo pulse widths (usually 1ms to 2ms) may not give you a full 180 degrees of motion. In that case, check if you can set your servo controller to custom pulse lengths and try 0.75ms to 2.25ms. You can try shorter/longer pulses but be aware that if you go too far you could break your servo!
Check out our example Arduino sketch which demonstrates how to record motion data to the EEPROM and then play it back when a button is pressed. Comes with a range of horns as seen above.