The base material of the top cover and the enclosure are made otelectro-galvanized sheet, with highly anti-corrosion parameters thannormal cold rolled steel sheet.

The upper cover is fabricated by a drawing die set, with a muchhigher strength than the welding process. lt also lacks thecorrosion of the joints caused by welding.

The bottom edge of the cover is a folding turn edging, whichmakes them more durable, and also prevents the possibility ofscratching the hands by the cover edge when dropping rubbish