... in air filtering field and general air adjusting system. Introduction: AF pre filter is a blue-white coarse filter, mainly applicable ... , better pre-filtration effect and higher air flow rate. Model: AF-200G; Specification: general stock 1m*20m, 1.25m*20m, 2m ... *20m. Also make according to customer's order. Model:AF-200G Weight:200 g/m2Thickness:18 mmMax. Airflow:1980 m3 ...