Applying special shipping costs/conditions for a category

[ghwebdesign]

I have a shop with about 200 items and have configured the shipping costs for everything without any issues. 

 

However, I have one set of products - 16 to be exact - and they are all sold and shipped in a slightly different method than the rest.  These items all need to be set to ship at a flat rate of $10 regardless of the number of items ordered from this category.  I cannot seem to figure out how to assign shipping to the group without it charging for each individual item. 

 

Simply put, if a customer purchases one of these items, it costs them $10 shipping.  If they order 47 of these items and a mixture of the 16 that are offered, it is still only $10 shipping. 

 

Does this make sense?  

 

I have searched and not yet found an answer and I need help asap. 

 

Thank you!! 

 

edit: Using prestashop 1.6.x

Edited November 9, 2015 by ghwebdesign (see edit history)