“Yeah, but how do I know it’s working?” Great question. Check out this real-time test we did… As soon as this Alen air purifier detects the smoke, the color ring instantly changes color to alert you of something bad in the air. Then Alen immediately goes to work, removing that harmful, stinky smoke and restoring pure air to your room. The color ring goes back to blue and you go back to breathing awesome and being awesome.