The reading is taken when an individual places his/her forehead 2-4 inches away from the thermometer. If the temperature is within a normal range, a green light will come on. If the temperature is a fever grade or high temperature, the red light will come on as well as an audible alarm signal. [ NON-CONTACT ] - Body temperature is detected within 2-4 inches away from the thermometer. The thermometer allows non-contact testing which helps avoid cross-infection among testers as well as eliminates the need for a healthcare worker. The thermometer can be operated independently without human assistance and the results can be later extracted on the computer. [ BLUETOOTH + ADVANCED TECHNOLOGY ] - Our thermometer includes a Bluetooth feature that allows you to connect to the thermometer and track temperature data for multiple tested individuals. You can use the feature by downloading a free app on App Store or Google Play and following the included instructions. Our thermometer also features advanced technology with an advanced sensor that rapidly delivers precise and accurate temperature readings. [ MULTI-PURPOSE ] - The thermometer is ideal for any sorts of public or private places: Business areas like offices, restaurants, bars, shops; Transportation areas like railway stations, subway entrances, bus stations, airports; Public places like schools, hospitals, museums, theaters, cinemas. The thermometer will make customers and employees feel and be safer which will help with attracting business during these hard times. [ EASY INSTALLATION ] - The thermometer comes with easy installation instructions. You can mount the thermometer by using nails, hooks, brackets, or included double-sided strong adhesive tape. The thermometer is powered by an internal rechargeable battery or an included USB charging cord. Package Includes: Non-Contact Infrared Thermometer 1 18650 Battery 1 FAQ How close does a thermometer detect temperature? Body temperature is detected within 2-4 inches away from the thermometer. How accurate is the device? The temperature accuracy will be in.18F range of a true value. I can not find the app in the App Store? You can use either a QR code that is attached to the instruction manual or you could search “Bluetooth thermometer” in the medical category and the creator is Min Zhu. What height do you recommend mounting it? There are no restrictions on the mounting height. You should mount it at your desired height. We would recommend 5’6 feet from the ground. Is it recommended for it just to remain plugged in at all times for the best results? Results will not change if it is plugged in or using the battery or both. How does the alarm system work? The alarm goes off on factory settings at 100F. If someone has a temperature higher than 100, the alarm will go off for 2 seconds and the red lights will turn on for 2 seconds. You can change the temperature at which the alarm goes off through the app. Can you export the temperature data from the app? Yes, you can! The data can be exported as a data table in any format and you can choose what dates you want to export. How long does a thermometer last? The approximate lifespan of the wall-mounted thermometer is 100,000 scans.