Monty just do one thing make sure you get one of those SD cards, put it in your unit and save all your information to it. Remember what happened to me with my GPS unit when PW & I followed you from Sparrowfoot to Hwy U bridge? It went down and I wasn't saving the information to my SD card so I lost all my information. I finally got that unit back up and working and purchased another unit but now I save all information to the SD cards.
I even purchased the mapping program that is on the SD card in my GPS units for my computer. I found it at BP Outlet store for less than half price. Still playing with it to learn it. But now I have the same GPS maps that I have on my GPS units now on my computer.