Each bulb has 2 leds, but they only face one side of the bulb, so depending on where they end up, some will look brighter than others on the roof. Some bulbs came broken right out of the box. Packaging was very poor for light bulbs.
The magnets are surprisingly strong. The plastic is very durable and didn't seem at all affect by the Aussie sun all December. It will work for fairy lights but may take some adjustment to hook/ clip.