I got these and was thrilled when I got them. Ran these in my house for a few days a few hours at a time and noticed the orange skulls dimming. Well, they're battery-operated, so I figured they were just starting to die. I was disappointed, but kept running them until I decided to switch the batteries. Unfortunately, they were still dim with new batteries. I'm not sure why, but the orange ones are completely dead, the purples are completely dead, and the green ones have a little tiny flicker of life in them. I probably got 20 hours of use out of them. Incredibly disappointing.