GE Plant Bulb, Wattage Rating: 40 W, Lamp Base: G13 Medium Bi-Pin, Lamp Shape: T12, Lamp Material: Sodalime Glass, Lumens: 1900 Lumens, Light Color: Cool White, Color Temperature: 3100 K, Color Rendering Index (CRI): 90, Average Life: 20,000 hr, Start Type: Instant, Dimensions: 1.59 in Dia x 48 in LSpecially designed to promote growth and flowering of plants and aquatic vegetationContains a combination of phosphors that produce light rich in reds and blues, specially designed to promote the growth and flowering of plants and aquatic vegetationLasts 9.1 years based on 6 hrs per day usage