Replace your Garmin Nuvi 300 Battery or Keep an Extra Battery on hand as a backup. This is an Extended Capacity 1250 mAh, Lithium-Polymer Battery that offers up even more up time than your original. Works in your Garmin Nuvi 300 GPS. Simple, Easy and Inexpensive! You get a New Battery, a FREE Torx Tool and Shim Tool (necessary for installation), a helpful Installation Video AND You also get a full ONE YEAR Money Back Guarantee exclusively when you purchase from us!