When adding/editing your Packages, you can mark any Contents as Required.

This'll ensure those items are always automatically added to the order.

You can also choose to leave items as not Required (or Optional).

This'll allow your sales team to quickly choose which Contents will be included within the Package. If your package is priced by contents, optional contents will affect the package pricing while keeping the individual items price hidden from your client.

Note: Package Contents will only adjust the price of the order if you are pricing your Package by Contents. Packages priced by Daily, Hourly, or Flat Fee will not have their price change when changing the Contents.