Features: Using advanced chip to accurately detect and monitor the concentration of formaldehyde(HCHO) and total volatile organic compound(TVOC). Immediately send out audible and visual alarm if the concentration of HCHO and TVOC exceed the normal level. Super easy to operate, long press the button to power on, wait for a 180s countdown, and it will automatically monitor the HCHO and TVOC contents. Easy to read, 3-color LED indicator shows you the level of TVOC - bad, normal, good. Precision air quality monitor features rounded shape, glossy surface, compact and lightweight, easy to carry around. Note: xBatteries not included. xUnder normal battery level, the unit will enter standby mode after 30 minutes if there is no operation taken. xUnder low battery level, the unit will enter standby mode after 5 minutes if there is no operation taken. Specifications: Brand: NOYAFA Material: ABS Color: White Formaldehyde Dectection Range: 0.000-2.888mg/m³ TVOC Detection Range: 0.000-9.999mg/m³ Unit: mg/m³ Power Supply: 2pcs 1.5V AA Batteries (NOT included) Item Size: 14x4.9x2.7cm / 5.51x1.93x1.06in Package Size: 16.5x9x3.2cm / 6.49x3.54x1.25in Package Weight: 100g / 3.53oz Packing List: 1 x Formaldehyde Detector 1 x User Manual(English)