Replace your Magellan Roadmate 3055-MU Battery or Keep an Extra Battery on hand as a backup. This is a High Capacity 750 mAh, Lithium-Ion Battery that offers even more up time than your original. Works in your Magellan Roadmate 3055-MU unit. Simple, Easy and Inexpensive! You get a New Battery, Video Instructions, FREE Special Tools (necessary for installation), AND You also get a full ONE YEAR Money Back Guarantee exclusively when you purchase from us!