Circline FC12T9 Fluorescent Bulb, 32 Watt, 12", 6500K Daylight.
Works in any standard 32 Watt Circline fixture, including Naturallighting.com Adaptor Item No's. CAD32,and CAD54.
Excellent daylight bulb for plant lighting. Not recommended for color matching because of high color temperature (blue white, and low CRI (Color Rendering Index). Sunlight equals 100 CRI, Daylight equals 82 CRI.