With Tax Free you are able to delete the taxes of the current item.
Sales Screen> Rang up item with taxes included
On the sales screen, you can see the applied TAX below the SUBTOTAL of the sale.
To remove the tax from a particular item, select it and press on the yellow TOOLBOX below it.
Press the icon TAX FREE to exclude the taxes from the item.
Result:
To restore taxes to the item, go back to the Item Menu and select REMOVE TAX FREE.