This is on an older tracker pro 128 DX locator,was thinking about an 83khz transducer but Ill just use it like it is till I can up grade to a better one. Im thinking I will use it to locate the holes and contours on the bottom. Now that you guys explained to me how these work,I have a better Idea where to drop my bait at,after all thats what these things are for,where to put your bait where you will most likely get a bite.thank you guys.....