square manhole cover with double seal type factory

1. material: ductile iron 500-7

2. class:D400 to EN124

3.frame weight: 50kg

ver weight:70kg

5.over all dimensions:800*800*100MM

6. clear opening:550*550MM

7. lifting holes: through(plugged with removable rubber stoppers)

8. frame and cover coating : black bituminous.

   thickness: 350μm 

9.COVER AND FRAME: DOUBLE SEAL TYPE