Callisto is a logging RFID tag with a temperature sensor and a clock to be able to periodically wake up and read a temperature value. A special protocol is used for communication with the reader. This protocol allows several tags to exist simultaneously inside the reader’s range. Every tag has a unique serial number. The electronics are of the highest quality and classed for extended work temperatures. The tag is powered by a lithium battery for the best possible service life. The plastic casing is moulded in one piece and thus completely waterproof. Standard colour options are blue, black or transparent and other colours can be specially ordered. Logotypes can also be applied in the moulding process.