yolink smart wireless temperature & humidity sensor, wide temp range (-22 to 158 degree) for freezer, fridge, green house, pet cage monitoring, smartphone alerts, works w/alexa ifttt -hub required yolink “yolink” is a proprietary wireless technology provided by yosmart. which is based on the semtech's lora wireless technology combined with the yosmart smart home/buiding protocol, to provide the most advanced smart home/buidling devices solution. compared to wifi, bluetooth, zigbee, z-wave, and other smart home protocols, it has the advantages of low-power consumption, long-distance coverage (wall penetration), and anti-interference. it is the first smart building/home protocol that can be very easily setup and is a very low cost but creates a reliable, robust and more secure iot network.