I bumped a hornets nest asking that question in another forum.Over 98% had nothing good to say about the trident and the Company that sells it as a PROfessional model.Some of my favorites were"barely finds a dime at 2 inches and sounds like an insect"and "cannot locate a volkswagon in a swimming pool".
So many complaints that the post was pulled.
It would appear that there are 2 Different detectors being sold under different names and Control boxes.IE A 2 knob,and a 3 knob
I would buy a used detector from An Established manufacturer with better customer support.
So I am saving to buy a Fisher 1280X.
Happy Hunting,Mont