The Gauge Blocks are length measuring standards. The accuracies conform to GB, ISO, DIN861, GGG-G-15C standards. They are used for length measurement. Gauge Block Set Table - ISO 3650Item No.   Pcs.per set    Class    Series of nominal size (mm)      Blocks in set    Weight (kg)901-16         112            1,2                 0.5~100                            3-49              2.317 (1.801)     -17          88             1,2                 0.5~100                            3-49              1.784 (1.387)     -18          47             1,2                 1~100                               2-22              1.456 (1.132)Note: in the parenthesis is the weight of ceramic gauge blocks.