AgroMax BIAX F55T5 Grow Bulb – 6400K is a 55-watt compact T5 fluorescent lamp designed for vegetative growth. The daylight spectrum bulb (described by AgroMax as 6500 K) outputs approximately 5,000 lumens and uses a 2G11 four-pin base. The nominal length is 20.7 inches and the rated life is 20,000 hours. This F55T5 lamp fits AgroMax PLL 55-watt BIAX fixtures and is commonly paired with the Tek Two and Tek Four fixtures for 2-foot form-factor lighting. The folded BIAX design concentrates fluorescent output into a short footprint, useful for propagation racks, shelves, and compact veg areas. Use as a direct replacement in any compatible PLL 55-watt BIAX fixture to refresh output without changing the spectrum.