This is a set of vintage bubble lights from yester-year. They start to bubble when plugged in for a few minutes. I have tested them. They all light up. One yellow light does not bubble though, or maybe I didn’t leave it plugged in long enough. Either way, it didn’t bubble for me, the other 6 did though. The strand measures 11’ long. They come in their original box and the box says there was one 1.5 amp replacement bulb, but I didn’t see it in the box. They were sold by May Department Store. These were in my sister-in-law’s shed and we are just clearing out stuff since she passed away.