Comes with two but one can be purchased if that's all you need. (1 for $15, both for $28) "Full spectrum - The full-spectrum Red + Blue + UV + IR design of the growth lamp is mainly used for small plants, suitable for various hydroponics, indoor planting, germination, plant growth and flowering. This feature is especially useful when plants need extra light in adverse weather conditions or in a dark room.(Note: UV and IR are dim, but normal.) Use Widely - Used in greenhouses, gardens, vertical farms, and growing tents. It can be used for hydroponic plants and indoor plants in soil, mainly for small plants, such as potatoes, tomatoes, and aquatic plants like algae. As a great aider during growth. High efficiency - As for LED power, this light board is very efficient and has good heat dissipation effect. Plants can grow fuller, stems stronger and straighter. Low power consumption saves you electricity bills." (Source: Amazon)