The F1R series is a single door, curb style, angle framed access cover with 625 lb. psf (28 kg. per sq. meter) load rating. This unit is commonly used on underground vaults located in areas that are prone to flooding. The F1R series is also ideal for access to potable water storage tank or vaults in areas where odor control is a determining factor. The unit is bolted to a structure directly above the existing opening.