I love these lights. They are a million times better than those arm led lights that are all over ecogrowhawaii.com. These actually work! My succulents are happy under them and they are so bright. The timer works well and I use it at 12 hours. The lights were easy enough to screw together. I am so pleased with these, they are just like the professional grow light boxes that hang from the ceiling, except they are adjustable, perfect for houseplants, and you can have one light lower than the other. Very reasonable price for such a useful grow light. I bought the three arm one first and then got a two arm one because of how great they are. They are so bright, they even sun stressed a few plants and turned their leaves pink. They just need to be spaced far enough away from sensitive leaves, but that’s how you know the grow lights are working. Several of my plants have put out new leaves as result, including two that suffered from root rot when I adopted them. Even my fussy calathea is unfurling a new leaf as we speak.