This is a postage option for orders that have preordered items also in with the order.
If you have an order with both available stock and items that are on a preorder basis, You have the option to add this extra cost to your orders postage to receive the items we have in stock before the preordered.
This means you will not have to wait the 2-3 weeks waiting time for the whole order to be sent at once. But have the option to receive the items we have in stock before the preorder items come in.
The available items will be sent within 3 days of purchase, and the preordered items will then be sent when they arrive.
This is available to people who do not want to wait. If you are happy to wait the 2-3 weeks then you do not have to choose this option.