Bloomerang T5 PL55 Grow Lights do not use regular bulbs with standard output, but instead operate PL55W High Output Bulbs. PL55W Bulbs are like two bulbs in one. With a full-length bulb coming out of the socket, a short connector in the glass, and a parallel full-length bulb going back into the socket, these PL55W bulbs shape a 4’ bulb into a 2’ socket. Bloomerang T5 Two Footers work exceptionally well with seedlings, clones, and moms. They also can support all stages of vegetative growth and the entire flowering stage. With a 10’ cord for easy distance mounting, top vents to move heat upward, and cool operating mixed spectrum bulbs, you’ll be able to place these fluorescent fixtures very close to the top of your plants and maximize lumen exposure. With simple ventilation, these fixtures will help your plants flourish throughout their growing cycle.