Wireless mission Thermometer LCD Digital Alarm Refrigerator Freezer Electronic Temperature Sens 1.Wireless signal mission distance without interference 100 meters, can display two different maximum and minimum temperature records at the same time. 2.\u2103 /\u02DAF unit conversion: Celsius and Fahrenheit display can be switched to meet and has strong signal penetration. 3.ALARM SETTINGS: When the indoor or outdoor temperature exceeds the preset minimum and maximum alarm values, the thermometer emit an audible alarm and a visual alarm to alert you and allow you to see if adjustments are needed. 4.EASY TO INSTALL AND OPERATE: Use the magnet on the back to magnetically attach the thermometer directly to your refrigerator or freezer, or place it on a table. 5.APPLICATION: Can be used in the refrigerator, freezer or indoors and outdoors to easily monitor temperature changes and provide double protection for your food. Parameter: Measuring range ( mitter): -40\u2103~60\u2103 ( -40\u2109~ 140\u2109) Tolerance: \u00B11\u2103 ( \u00B12\u2109 ) Temperature Resolution: 0.1 Wireless Frequency: 447.6MHZ Wireless range: 100 meters without obstacles Main unit size: 95x62x20mm mitter size: 95x36x20mm Use of power: (default delivery without batteries) Host: 2pcs 7 batteries (AAA) mitter: 2 pcs of 5 good batteries (AA) Colour:White Material:plastic Package Contents: 1 x Thermometer 2 x mitter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is + /- 1-3cm.