I buy this device over a year ago and could not be happier . I have loan it a couple of my friend who immediately buy one just like it . one of those friend have one build into he Denali but use this one for it be user friendlyness and ability to move it from car to car . the other have just buy one of a different brand and ask I to come over to help he learn how to use it . I could not make sense of he so loan he mine . with out instruction he be able to master the c340 and immediately take the other one back for a refund and buy c340 . the only caveot be it do not come with rubber dash mount which by the way work great , so plan on get one when you buy you c340 .