Red spectrum Ultra Grow LED light bulb. Features a deep red light appearance that is perfect for fruiting, flowering, and blooming. The unique mixture of red light supplemented with full spectrum daylight activates the photoreceptors responsible for flowering and fruiting in plants to encourage growth. With virtually no heat signature, it replaces hot floodlight bulbs up to 150 watts, and can save you up to $133 per year on electricity per bulb. A19 shape with standard E26 (medium) household base.