1) SS304 316L2) Size: 410x510, 320x440, 350x450mmYAC:arc manhole cover,which can sustain a Max.Static pressure of 2bar(under the temperature of 20°C) YAC-1:arc manhoe cover,has higher bracket,suitable for big vessels with lagging material. YAC:flat manhole cover,lower bracket.YAC:flat manhole over,,higher bracket,suitable for big vessels with lagging material.YAC-P:can sustain a Max.Working pressure of 5bar