I picked up this one second hand.
It's an Intelli IMT-500, obviously a cheap copy of Intellituner.
It tracks very low, even to low A and isn't bothered by ambiant noise.
However it is very slow and not so accurate. The clench tends to vibrate when not properly seated.
It works for me because I mostly use it home. A casual tuner, so to say and you can't beat the price.
Now I wouldn't recommend it for serious tuning.