The lights have to go into the slots, if I remember correctly from what I've got at home.
The light is just ok, in terms of growing plants. Low light plants should be fine, but that's about it. Based on my eye test alone, it's probably equivalent in light output to the Marineland LED double strip.
The positive feature about it is the ability to switch out light strips to create different light effects and that if the lights burn out, you can just replace the strips at a reasonable cost.