AirKnight Default sorting Sort by popularity Sort by average rating Sort by latest Sort by price: low to high Sort by price: high to low Sort by editor review Added to wishlistRemoved from wishlist 0 Add to compare 9-In-1 Indoor Air Quality Monitor Indoor & Air Quality Sensor by AirKnight Monitoring. VOC detector, CO2 Monitor, Formaldehyde Detector HCHO, AQI, PM2.5, PM10 Temp, Humidity. Air Monitor AQI CO2 Meter Added to wishlistRemoved from wishlist 0 Add to compare $99.99