I bought four bulbs and three of them didn't work. I thought it might be the device so I bought a new one. Still does not work. I paid an electrician to check the wiring. Still does not work. Then it turned out that the light bulbs were defective, not the lamp, and not the wiring. Very disappointed. Cannot return them for a refund as the electrician took them to be properly recycled. It was a very expensive and frustrating lesson. Beware.