... steel gratings Trench coversUnique features:1.Attractive appearance : clear and smooth figure, silvery appearance, modern-styled. 2.Optimal drainage ... squares, gardens, wharf, airport, parking, highway, railway, industrial engineering and so on.Type of bearing barW--welded steel grating L ... without edge, U-type Trench covers are very easy and economical. 3. Security type: steel grating hinged pit ...