Product name: Circular Manhole cover( without pressure) 
Material quality: SUS304, SUS316L 
Specification: 400mm, 430mm, 450mm, 500mm, 600mm 
Standard: 3A/DIN/SMS/ISO 
Applications: Beer, dairy, beverage, pharmacy etc. 
If you are interested in our product, or need any more information, pls don't hesitate to contact us.