This object provides the value of the declared dimension, in the feed direction, of custom that is (or, if empty, was or will be) in this input sub-unit. The feed direction is the direction in which the media is fed on this sub-unit. This dimension is measured in input sub-unit dimensional units (prtInputDimUnit). If this input sub-unit can reliably sense this value, the value is sensed by the printer and may not be changed by management requests. Otherwise, the value may be changed.