Filters feature 30, 60, or 90°-slanted honeycombs. Units with the company's Quadrafoam filter media comply with Telcordia GR-487-CORE requirements for flame, fungus, and corrosion resistance. Those with Quadrafoam II also withstand dust intrusion and wind-driven rain. Filters for indoor use direct laminar airflow towards concentrated areas within the chassis. Universal Air Filter Co., 1624 Sauget Industrial Pkwy., Sauget, IL 62206, (800) 541-3478,