I bought a few of these to use in my Magellan Navigator. Some rival cards don't seem to work in the Magellan and one other brand kept losing its program when I left the Magellan in strong sunshine which is normal since it is stuck to the windshield! These cards work great and the "lock" feature which works similar to the old window plastic clicker on a 3.5 inch floppy ensures I do not overwrite programmed cards. I fully recommend these cards.