Simply the best thing I have purchased for my Garmin Vista Cx.It has the detail of the roads I wanted from the start of using a GPS unit.It needs to be cleared up, the matter of it can only be loaded on a computer2 times. You can load it on a computer as many times as you want. Garmin will only let you use it, or I should say support it, with 2 of their GPS units.I have never been sorry I purchased it, Kinda a little pricey...KB