How do I add or remove units of measure on quotes and invoices?
You can add or remove the units of measure of your choice directly in editing mode for a quote or invoice by clicking “Manage” at the bottom of the units list. You can also access this setting directly from the main menu “Settings > Units”.
Link to this article:http://toolcie.com/en/support/k/how-do-i-add-or-remove-units-measure-quotes-and-invoices