A 3x3" air mass filter specifically designed for Sciencetech's Fully Reflective Solar Simulators, including filter holder. The AM1.5G simulates the terrestrial solar spectrum on the ground when the sun is at a zenith angle of 48.2°. It includes both direct light from the sun, and the diffuse light that is scattered by the atmosphere. As a result, this filter simulates the total radiation, known as global radiation, which reaches the ground.