1.Wireless signal transmission distance without interference 100 meters, can display two different maximum and minimum temperature records at the same time. 2./F 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 (transmitter): -40~60 ( -40~ 140) Tolerance: 1 ( 2 ) Temperature Resolution: 0.1 Wireless Frequency: 447.6MHZ Wireless range: 100 meters without obstacles Main unit size: 95x62x20mm Transmitter size: 95x36x20mm Use of power: (default delivery without batteries) Host: 2pcs 7 batteries (AAA) Transmitter: 2 pcs of 5 good batteries (AA) Colour:White Material:plastic Package Contents: 1 x Thermometer 2 x Transmitter 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.