GPS-Buddy Fuel Economy Software Module provides the ability to track and trace vehicle travel history for analysis of routes taken and will indicate cost per mile. Requires compatible Garmin PND device to be turned on in the vehicle during any trip you want to review. Compatible with the following Garmin GPS units: Nuvi Models: 205, 205W, 255, 255W, 265T, 265TW, 275T, 500, 550, 710, 750, 760, 770, 780, 755T, 765T, 775T, 785T, 850, 880, 5000 Zumo Models: 400, 450, 500, 550.