Engel USA Wireless Cooler Thermometer Wirelessly monitor your fridge, freezer or cooler temperature from up to 100 yards away Place the receiver on your dashboard or in your galley and easily keep Track and monitor the temperature Battery life: approximately 24 MONTHS Receiver: 2Xaa Lr6 Alkaline batteries - transmitter: 2Xaaa Lr03 Alkaline batteries Includes two hook and loop fasteners with adhesive backing