Bulbtronics has the largest selection and best prices on all Fluorescent products. Bulbtronics is the brightest source on Earth. The 99 FL10D is a 10W 13.5" T8 PREHEAT LINEAR Fluorescent lamp with a G13 / MEDIUM BI PIN base.Bulbtronics is your source for all lighting and other electrical products and equipment. For more detailed specifications for 99FL10D , please look below.