I'LL have to check in the morning. It's a digital gauge with a white face and appears to be the OEM gauge from Harris. It has arrows to adjust the depth setting for the alarm, but not sure how to adjust or if it can provide real time depth readings.
The three most common would be Lowrance, Humminbird, and Uniden. Get your model number, or at least be able to identify it from Google images and you'll be able to decipher a model number from that.
As far as 'real time' depth readings, during the setup phase, you'll tell it how often to reread a signal. I have mine set to reshoot 2x per second.