I would have left a 5 star review except for the fact that the seller only communicates through Amazon and not her website. I bought this item and received it but it had a burned out bulb. Amazon replaced it
. The second unit was also defective. It would work fir a few seconds, then stop working, then work again and go through this on and off cycle until it timed out. I returned it to Amazon and their policy was no exchange for the second item, only a refund. I originally left a 1 star review based on my experience. Based on the review, the seller communicated with me offering a third item at no cost to me if I would delete my review. I told her it was a deal but if this third unit was defective, the review would be reinstated. The third unit works the way it is supposed to. I really needed this unit to disinfect my basement after a massive sewer backup that affected a large portion of metropolitan Detroit. I AM NOW A HAPPY CAMPER and am so glad I gave this item another chance. I have used dosimeters to measure the amount of UV emitted by this device. It is putting out enough to kill just about any pathogen including e-coli nd the Covid virus. THE LIGHT IS DOING ITS JOB.