AC Infinity’s Duct Air Filter Box 4" with High Efficacy Filter is a steel, inline filtration enclosure engineered for fresh‑air intake with 4‑inch ducting. It includes a removable pleated high‑efficacy filter and accepts standard 12 × 20 × 1 inch MERV replacements to capture 0.3–1.0 micron particles such as dust, dirt, lint, and odors. The matte black, 1 mm cold‑rolled steel housing with aluminum flanges is weather‑resistant and features a hinge‑sealed, slide‑lock door with a neoprene gasket for a dust‑tight seal and easy servicing. Rated up to 400 CFM airflow (about 680 m³/h), it integrates with CLOUDLINE S4/T4 or other 4‑inch inline fans. Overall dimensions are 23.46 × 8.42 × 11.73 inches (59.6 × 21.4 × 29.8 cm).
