Engineered to prevent employee injuries and deaths from falls through skylights, non-penetrating Skylight Defender meets and exceeds 200 lb national OSHA regulation as well as California OSHA mandates by withstanding and supporting at least 400 lb. System fastens onto skylight frame using compression system and requires no drilling. Constructed of welded galvanized mesh, Skylight Defender has wire screen thickness of ¼ in. for complete skylight protection.