Trunk doesn't yet support unit measurements so therefore you'll need to convert them to multipliers. For example, if you needed to keep various lengths of fabric synced such as:

you'll need to first create the lowest unit product within Trunk in which all multipliers can still be whole numbers. In this case, it probably makes most sense to use centimeters.

We'll need to first create a product within Trunk that represents 1 centimeter (please refer to this article on how this is done). After that, it's very similar to how quantity packs are created.