Description: Features: brand new and high quality Simple, fast and economic way to determine whether formaldehyde gas (HCHO) is present in your home environment. This test kit is suitable for all living areas up to 270 square ft. (25 square meters). One kit per room(item). Caution: 1. The longer the test area kept closed before measuring formaldehyde the more reliable results you get. 2. This test will provide only visual results of what is the concentration of Formaldehyde in the room and should only be used for home or office environment and not compared to industrial equipment. 3. If Formaldehyde Gas is present in your environment we recommend purchasing an air purifier or any other Formaldehyde removal technology to protect yourself and family. Since long-term exposure to Formaldehyde can cause serious for health problems. Storage: Please store the test kit prior use in a dry and dark place. The expiration for time is 2 years from the production date. Instructions: 1. Before the text close the room for one to three hours with all ventilation, air purifiers, humidifiers and air conditioning turned off. Keep the air temperature and humidity constant during the test. A more stable test environment will creat more accurate results. 2. Open the absorption box using any for sharp tool and cut gently around the edge. Pour all absorbent(white bottle) into the opened absorption box. Specification: Detection range: 0.00-1.80mg/m Detection of space: 25m Package box size: approx. 10x7.5x2cm(3.94x2.95x0.79in) Color: As pictures shown. Shelf life: 2 years Quantity: 1 set Note: Transition: 1cm=10mm=0.39inch With retail package. Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1 x Self-Test Box 1 x 20 Levels Colorimetric Card 1 x White Test Tube - absorbent 1 x Brown Test Tube - color developer 1 x Absorption Box - white cylindrical container(other accessories demo in the picture is not included.)