Rationalkeys Studio ships some items from Tampa, FL and some from items from Istanbul warehouse.
When an item is shipping from Istanbul Warehouse you will see Express Shipping as shipping method. Our system picks whichever carrier provides the happy median of fast and cheap. We use DHL, Fedex and UPS as shipping carriers when shipping from Istanbul.
When an item is shipping from Tampa, FL, your rate will be calculated by Shopify and you will be able to choose between shipping methods that are provided.
Contact us at firstname.lastname@example.org if you have any questions about our shipping process on a particular item.