This four-channel temperature humidity meter which can display indoor & 3 outdoor temperature and humidity simultaneously, is great for home use. It is suitable for desktop placing or wall hanging. Large LCD display, you can easily read the data. Accurate measurement for measuring indoor & outdoor temperature and humidity.Features:Display four-channel indoor & outdoor temperature and humidity at the same time with / temperature unit for selection.Adopt wireless technologyyou can know 3 outdoor temperature and humidity in indoor receiver.Record max/min indoor and outdoor temperature and humidity with temperature trend indication.Alarm function of upper and lower limits of indoor and outdoor temperature and humidity.Can be placed on the table with a bracket or hung on the wall with a hanging hole.With 3 portable transmitter to induce 3 outdoor temperature & humidity and transmit within 100m without obstacle.Temperature humidity meter is powered by 3 * 1.5V AAA batteries or DC 5V, each transmitter is powered by 2 * 1.5V AA batteries.(Not included)Specifications:Material: ABSColor: Silver + WhiteDisplay: 121 * 106mm LCD DisplayIndoor Temperature Measuring Range: -1060 / 14140Outdoor Temperature Range: -5070 / -58158Temperature Accuracy: 1Indoor Temperature Humidity Detection Period: testing once 30 secondsOutdoor Temperature Humidity Detection Period: testing once 57 secondsHumidity Measuring Range: 2095%RHHumidity Accuracy: 5%RHFunction: Indoor/Outdoor Temperature and Humidity, Max & Min Value Display, Comfort Level Display, / Switchable, 3 Separated TransmitterBattery of 3 Transmitter: Each 2 * 1.5V AA Batteries(Not Included)Temperature Humidity Meter Power Supply: 3 * 1.5V AAA Batteries or DC 5V (Not Included)Size of Transmitter: 123 * 45 * 25mm / 5.12 * 1.57 * 0.87inTemperature Humidity Meter Size: 169 * 163 * 26mm / 6.7 * 6.4 * 1.0inTransmitter Weight: 56g / 2.0ozTemperature Humidity Meter Weight: 219g / 7.7ozPackage Size: 21 * 19.6 * 9cm / 8.3 * 7.7 * 3.5inPackage Weight: 590g / 20.8ozPackage List:1 * Temperature & Humidity Meter3 * Transmitter1 * User Manual