... capacity, can be used in wharf,airport etc.Application:urban road, public squares, gardens, wharf, airport, parking, highway, railway, ... easy and economical.3. Security type: steel grating hinged pit covertheftproof design: the cover and the frame are connected with hinges, ... ditch covers:5. Installation type:Introduction to common steel grating:Bearing bar centers at 20mm: This kind of fine mesh ...