If you book the value added service rehearsal packaging, your items will be packed into a parcel that's exactly like the configuration you want to ship internationally.
It will then be weighed and measured .
This allows the agent to give you a shipping estimate that's a lot more precise, the margin of error should now be < 5%, down from up to 60%.
That is the main purpose: get a lower shipping estimate.
For shipping lines that have a weight restriction, such as EUB (< 2kg), this could be the difference between being able to select the line or not.
the cost of this service is usually $1-$3. This will almost always be worth it.