• This is only for buyers to pay an extra shipping fee/price difference.
• Kindly remind, this item is not a product.
• Don't order this item without purchasing other products in our store.

This link for you to pay the price difference in the following situations:
1. When you already have placed an order, but you want to change it to a larger size or change from standard iron door to thermal break iron door, or change the specs on doors that has been made. 
2. When you request expedited shipping service for your order.