Blue spectrum Ultra Grow LED light bulb. Features a deep blue light appearance that is perfect for early growth of seedlings and optimal growth height in the vegetative stage. The unique mixture of blue light and full spectrum daylight encourages dense plant growth and healthy leaf development. 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. Ideal for seed starting and early growth DIY indoor gardening.