The 7710 is a piece of junk, so bad that the company discontinued it after 1 yr. I had to send mine back twice and it is broke again. Locks up and will not charge properly. There is no Customer service. The poor people in tech support try and are quick to have you send it in, but to no avail. I need a unit that will not foul out within 200 miles into a 1800 mile trip. I tried three times to contact them via their site email and have yet to get a reply. This is the poorest company I have ever done business with in my life. Buyer Beware if you want to do business with Rand McNally.