Exo Terra Repti-Glo 10.0 Fluorescent Lamp, 20-Watt/24-Inch Ideal for desert dwelling animals High UVB output; Effective up to 20 inches Provides necessary UVB rays for optimal calcium metabolism Recommended for use with screened terrariums; terrariums with dense screen covers (screens can filter out UVB rays) T8, 24 inch long light bulb; 20 watts