1)material: Steel
2)type: A--single-side acting watertight hatch cover
B--double-side acting watertight hatch cover
C--quick acting watertight hatch cover
D--sunk watertight hatch cover
E--single-side acting non-watertight hatch cover
F--double-side acting non-watertight hatch cover
3)dimensions: 450x630, 530x530, 630x630, 630x830, 830x830, 830x1230, 1030x1030, 1330x1330mm
4)certificate: CCS, ABS, GL, DNV, LR, BV, RMRS, NK
5)standard: CB/T3728-1995