The Final Filter, an in-duct air filter for fabric duct, is cone-shaped and is designed to zip in place within minutes at the inlet into a fabric duct system. It supplements primary filter systems in new or retrofit buildings with the company's air dispersion. The Final Filter is available in MERV-8 or MERV-12 nonwoven 3M filter media with 50-percent and 90-percent efficiencies, respectively, says the company. The multilayer custom filter media was developed specifically to withstand pressure loading while allowing depth loading. Depending on the inlet velocity, media, and sizing, the filter will generate 0.24- to 1.98-inches water gauge resistance to airflow, says the manufacturer. Designed for all of the company's round fabric duct models ranging from 12 to 72 inches in diameter, the filter comes in three lengths: a factor of 4, 6.5, or 9 multiplied by the diameter, the company says.

DuctSox, 8900 North Arbon Dr., Milwaukee, WI 53223; 866-382-8769, ext. 6055; www.ductsox.com.

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