The door and window thermometer is a pointer type meter. The internal precision bimetallic is to the temperature change of the detection environment. The product does not need any battery. Double-sided adhesive strong and coated, the product has a rain-proof function, the function of the product is not affected by a environment. It can accurately and quickly measure the outside temperature. Feature - ColorTransparent - Material: Acrylic. - Size: 11 cm in diameter. - The door and window thermometer is a pointer type meter. The internal precision bimetallic is to the temperature change of the detection environment. The product does not need any battery. - 3MM thick clear acrylic plate is used as a thermometer dial and the heart of the watch is stainless steel. Double-sided adhesive strong and coated, the product has a rain-proof function, the function of the product is not affected by a environment. It can accurately and quickly measure the outside temperature. - How to use: Wipe the outside of or door with a cloth, tear the protective film on the double-sided adhesive, hold the product and place the product outside the window or on the glass in front of the door. By closing the window or door, you can read the outside temperature inside. - Cleaning Method: A double-sided sticker is a plastic tie. The product can be removed from the plastic fastener. Once the dust on is removed, the product can be conveniently looped. for every room in the house. - Warm Tip: Dear buyer, due to lighting effect, monitor’s brightness, manual measurement, etc., there could be some slight differences in the color and size between the photo and the actual item. Sincerely hope that you can understand! Thank you! Package list: 4 x Thermometer