Hello, is it possible to add extra unit definitions to an invoice?

Specifically, meat is sold by the kg.

However, it is delivered by the case or the piece. The receiver sees two cases and a piece of meat (in a bag) and signs for those three items.

Example: Item A002-2004  | 2 Cases | Boneless Beef [15.6] [14.7] |  30.3 kg |  $4.00 per kg  | $121.20

(in the above example, the prepared cases were 15.6 and 14.7 kg, respectively, adding up to 30.3kg).

It seems that one cannot do that with SAGE50. one can only sell by the kilogram.