Sunlite 30345-su f28t5/865 28w fluorescent t5 bulb, mini bi-pin, daylight the fluorescent 28 watt 6,500k daylight t5 high performance straight tube features a mini bi-pin base, provides a light output of 2,500 lumens at a color rendering index (cri) of 82 and can last an average of 20,000 hours.