Exo Terra Repti-Glo 10.0 Fluorescent Lamp, 40 Watts, 48 inches Ultra high UVB output. Effective up to 20 inches Ideal for all desert dwelling reptiles Provides necessary UVB rays for optimal calcium metabolism Recommended for use with screened terrariums; terrariums with dense screen covers Recommended in combination with Repti-Glo 2.0 for a higher visual light output