It is a compact CO2 detector that is also capable of measuring temperature and humidity. This small device warns if humidity and CO2 levels are considered too high or low, which decreases comfort when staying in the affected indoor spaces. If the carbon dioxide concentration exceeds the recommended concentration for a ventilated room, this gadget alerts you that it's time to ventilate the room. There are digital indicators on the color LCD screen, and audible alerts are also available. If preferred, the buzzer can be turned off. Another useful feature of the Levenhuk Wezzer PLUS LP90 CO2 detector is the history of the maximum and minimum measured values. In addition, the tool calculates the average CO2 level every 15 minutes for 8 hours.Power supply: 5V, 500 mA AC/DC adapter not included.1.5 m USB cable, included. Diameter 12 cm, width 7.5 cm.White plastic body.Made in the USA. Gross weight: 250 grams.