Where in the product can I store the customs value?

[NigelShaw]

Where in the product can I store the customs value?

Every time I create a shipping label it asks  "Add item value to customs declaration to see shipping services." So I click that, add a value and check the box that says "Save to product details". 

Next time I create a label, same thing, it asks me for item value for customs declaration. 

Thx. 

Nigel