Anti-sound, Anti-slip, Anti-theft, Anti-drop,Anti-displacement, Easy to open, etc.
Anti-sound: We add anti-sound rubber ring on interface between cover and frame.
Anti-slip: We cast geometric pattern on manhole cover surface, The walling crib of manhole cover uses a ring to ring structural form and it also sets up bulge to Increase the resistance coefficient so that increasing resistance coefficient of bitumen material after  auxiliary road and the well ring.
Anti-displacement: There is fixing of anchoring bolt between walling crib and ground., it will avoid staggered joint when road roller compaction under inspection  cover construction, achieve standard construct.
Anti-drop: As to new model multiple prevention inspection manhole cover,owing to it has the anchor bolt and it can be crushed by the backfill of the inspection well circle  so that the compactness can meet normative requirements. Therefore, it avoid problems such as local settlement and cracks in the inspection well circumference caused by false back filling .

Anti-theft: The manhole cover is equipped with anti-theft secret box,  folding plate under the walling crib instead of anti-theft chain, which completely plays the anti-theft operation, and fundamentally eliminates the rust problem caused by cavitation and water erosion.