Feature●【EASY TO OPERATE】: just pressing the power on/off button, A button realizes all operations,design with LCD Color Screen Digital Display, it can offer mean value for each gas,It helps detect harmful HCHO and TVOC around your room.Description 【EASY TO OPERATE】: just pressing the power on/off button, A button realizes all operations,design with LCD Color Screen Digital Display, it can offer mean value for each gas,It helps detect harmful HCHO and TVOC around your room.