The Smith Rigid Cell has been engineered to provide high-efficiency filtration combined with prolonged life cycles. It is an ideal choice forvariable air volume systems. Being totally rigid, it’s performance is not affected by changes in air velocities or system shutdowns. The high surface area to depth ratio provides a maximum amount of effective filter media in areas of minimum in-line duct space. The Smith Rigid Cell isavailable in four efficiency ranges, Merv 14, Merv 13, Merv 11 and Merv 9. It is available in a box type (without a header) and also in a single header style. It is designed for use in a wide variety of applications includinghospitals, office complexes, and industrial facilities. High-density microfine glass available upon request.