The AgroLED® iSunlight® VEG + UV T5 replacement LED lamps are designed for the vegetative period of your plants' life cycle, featuring 80% 5500° K, 10% 460nm blue and 10% 380 nm UV. These iSunlight® T5 lamps are an intelligent LED that are specifically designed to work with your existing T5 fluorescent fixture. These LED T5 lamps are environmentally friendly and mercury-free. Not compatible with HF Agrobrite T5 fixture.