Dimension: 22"l x 22"w x 2"h Recommended for pedestrian, bicycles and wheel chair traffic. Open Area: 102 Sq inches Flow rate: 134 GPM Made in the USA This round flat green grate is constructed of a high density polyethylene, with UV protection to prevent fading and eliminate sun damage. With a unique grate pattern that not only increases flow, but blocks large debris from entering your drainage system this is a great solution for you next drainage project. Dimension: 22"l x 22"w x 2"h Made in the USA.