Everything you need comes with the unit. Lowrance you have to get the side scan transducer it don't come with it. I have the humminbird 1197si combo and the 787ci and love them and didn't have to by anything extra. Plus you can up grade your unit software on the website with all the latest stuff like down image map updates options all kinds of stuff well worth the money to spend. Found all kinds of new honey holes since I've got mine on lakes I thought I new pretty good. And I know what actually makes the spots I like to fish good and know where the sweet spot is exactly.amazing details you know what's on the bottom like rock ,stump, grass,trees, ledges,sunken road beds and on and on and on. I could go on all day about humminbird. Great company quality product.