Used factory produced Garmin Li-ion Battery Pack for Alpha 100, Alpha 200/200i, Alpha 300/300i, Aera 660, Monterra, Virb/Virb Elite, Montana 600, Montana 600t, Montana 610, Montana 610t, Montana 650, Montana 6650t, Montana 6680, and Montana 680t GPS handhelds . Production years vary and some are 3.7Vdc/2000mAh/7.4Wh and others are 3.7Vdc/1960mAh/7.25Wh. A free online software update from Garmin may be required to operate these batteries in your GPS handheld