ubibot ds18b20 temperature probe, waterproof external probe for refrigerator,remote temperature monitor for hot tub,swimming pool,-55 to 125 c,usb connector (matches with ubibot ws1,ws1 pro only)(3m) ubibot the ds18b20 is a waterproof external temperature probe designed to operate in extreme conditions (-55oc to 125oc). the micro usb connector is compatible with all our smart monitoring devices including the ws1 and ws1 pro. the probe is made from high quality stainless steel, so it won¡ ̄t rust in any conditions. the flat cable allows you to use the probe in sealed environments like refrigerators or freezers, and the different cable lengths are designed to offer you maximum flexibility.