The Ring Panels / Links from Brookaire Company contains specialized media and filter designs which optimize particulate filtration, airflow increase, and maximize energy utilization in each application. Media layers are graduated density for optimized dust loading and high energy efficiency. · Engineered internal frame assures stability under high air velocity and heavy dirt loading. · Airtight seal is created with our unique overlapping edge to prevent dust bypass. Our seal pattern improves filter life by preventing sagging and fluttering. · Custom sized panels and media combinations are available.