Filter sediment and oil from stormwater runoff flowing into rectangular storm drains with catch basins using this adjustable-frame filter that won't fall in. Adjustable frame expands & contracts to fit your drain. It's an easy one-person job to install, maintain or remove. Frame stays inside the drain making it perfect for parking lots and areas with vehicle traffic. Four-stage filtration from top to bottom increases the amount of pollutants captured. The patented filter ring channels water to center of collection bag to prevent untreated water from escaping through overflow ports. This adjustable frame storm drain filter helps you meet 40 CFR 122.26 when used as a Best Management Practice. Max Flow Rate is 400 gallons per minute. Dimensions: 32" W x 32" L x 16" H. Opening Dimensions: 8” Diameter.