SPRING SLEEVE GRATE
We according to the ductilly feature of the duction iron's in the open both sides and opposite, we design it triangle spring stucture . prevent covers take off and dislocation, also open arbitrarily etc. function: slip lines, anti noise, effectively reduce the noise impact manhole cover and base.
Use non-toxic water-solubility black paint
Widely used in municipal, water conservancy, electricity, highways, etc.