Looking for a reliable way to monitor the temperature of your fridge, freezer, or other spaces? This 2 - pack temperature sensor is the perfect solution. It offers real - time temperature monitoring via Bluetooth, allowing you to check live and historical data on your smartphone. With a high - precision 2.7mm NTC probe, it has a ±0.9°F/±0.5°C accuracy and a 2 - second response time, covering a wide range from - 40°F to 158°F (-40°C to 70°C). The built - in 80dB audible alarm alerts you when the temperature goes out of range. For remote monitoring, it supports gateway H5151, giving you 24/7 tracking and instant alerts. One gateway can manage up to 10 sensors within a 230ft (70m) range, enabling centralized monitoring of multiple areas. Ideal for busy families, it ensures the safety of your food and medicine. Each sensor measures 4.65 x 4.09 x 2.64 inches and weighs 7.4 ounces, with a packaging size of 4.6 x 4.1 x 2.7 inches and a packaging weight of 0.46 pounds. Get this sensor pack and enjoy worry - free temperature management!. Material: Plastic.