Quantity unit:

Dropdown list for selecting a unit. The available units will vary depending on the type of units selected in the General tab. (Metric or US units).

Qty title:

Set the name of the quantity.

No. dec.:

Set the number of decimals shown.

Default:

Set the default value for this quantity.

Merge:

Select the merge operation for this field. The possible operations are: 1, sum, unit wgt., wgt.avg., average, count, min and max.