MEATER Plus is 100% wire-free, allowing you to cook with complete freedom and flexibility. With its innovative technology, the Long Range Model is the world's first truly wireless meat thermometer. You can easily monitor your cooking progress using the free app, which is available for both iOS...
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I'm using a Meater Plus for monitoring temps and it works well. Nice because it also monitors the ambient air temp inside the cooker. The app can set notifications (alarms) for both high and low temp points. Easy to use with the WSM because there are no wires to mess with.
Yes... I compared it to readings with my Thermapen Mk4 poked through the grommet and they matched.
Only thing I notice is when the meat is real cold at first the Meater ambient reads a little lower (ten or so degrees) than the actual temp I think because of its proximity to the cold meat. After ten minutes or so as the outside of the meat warms up, the reading comes up and matches the Thermapen.