Flow Right Filter Cabinets are Ready-To-Assemble (RTA) filter boxes for HVAC systems. Featuring a patented knock-down design, they ship flat for easy storage and assemble in minutes, reducing installation time and costs. Made from durable galvanized steel, these adjustable height cabinets improve airflow efficiency by up to 20% compared to traditional 4-inch media air cleaners, reduce equipment strain, and can function as a booster box without the filter door. Adjustable height adapts from 4" to 18". Ready-To-Assemble (RTA) design allows fast setup. Ships in a flat carton for easy storage. Installed with or without a filter door, functioning as a booster box.