Stainless steel covers Dayi Metropolis covers stainless steel manhole cover Metropolis Qionglai Qionglai covers covers covers Dayi economy * Covers the selection can be galvanized steel or stainless steel frame and an inner frame main structure are thin plates with one-time molding, folding bent and welded this structure is conducive to enhance their strength, the bottom and then welding a thin rectangular plate due to the selection, which greatly reduces the cost of materials can be adapted to the pedestrian streets, sewers and other green bearer lower requirements