The Additional ProTemp S1 Base Unit expands your ProTemp S1 system, allowing you to monitor multiple smokers or grills with one main unit. Simply align and rotate the main unit onto the base for secure connection, enabling temperature tracking from different locations. Features: A high-end Platinum temperature sensor, This base unit withstands up to 1000°F (530°C) inside your grill. It’s weather-resistant and rainproof, Ideal for outdoor use, though we recommend keeping the main unit indoors when not in use. Compatible with Chefstemp wireless probes and the Breezo Fan for full control. Package Included: 1 x Base Unit 1 x S1 Digital Gauge Versions The thermometer its self is standard and always the same version. It's simply the base that varies; the standard base fits all BBQ's apart from the Big Green Egg.The Big Green Egg version has a much thinner thermometer stalk to suit that BBQ, so make sure to select the correct version.