This innovative reflector is carefully engineered to reflect light back down onto the foliage of the plants growing underneath. And more light means bigger, healthier plants! The highly reflective curved surface redirects light that would otherwise be lost to the surroundings, sending it down onto plants. This thin reflector fits behind the fluorescent bulbs of our T5 light fixtures that have black bulb socket ends. Simply remove the bulb, snap in the reflector, and replace the bulb.