This came with a recently purchased grill but I already have a preferred thermometer. It retails for about $64.
Make grilling the perfect steak or roast even easier with the Napoleon Grills PRO Wireless Digital Thermometer, it will let you know when the meat is done! The temperature probe is made from durable and rust-proof stainless steel connected to the main unit by braided wire to ensure that meals are cooked to perfection. Remove the digital display from the base and bring it with you. The display features easy-to-use controls and a clip to fasten it to your clothes or apron. This wireless thermometer will display accurate readings from 200 feet away, in English, Spanish, French, or German. Whether you are refining your favorite cooking techniques on the barbecue or learning an entirely new way of preparing a meal you need a Napoleon Grills PRO Wireless Digital Thermometer!