Description The OPW 1-2100-PEVR 5 Gallon Duratuff® II Base Thread-On Spill Container w/ Aluminum Cover and Plug is designed to prevent spilled product from entering the soil near the fill and vapor return riser connections on underground storage tanks during normal tank filling operation, or in the event of tank overfill. OPW Thread-On Spill Containers screw directly onto 4" NPT riser. No external connections to make; adjust the final grade height and support the unit with backfill. PEVR model is a vapor port with plug. The spill containers catch spillage to help prevent soil contamination and groundwater pollution. Key Features Highway 20 Rated (H20) Heavy Duty Mounting Ring Aluminum Rain Shedding Cover Capacity: 5 Gallons (19 Liters)