Ru9 offers free shipping nationwide for orders over 1,500,000 VND. For Ru9 mattresses specifically, if customers want to exchange the size within the first 100 nights, Ru9 will charge a shipping fee of 300,000 VND/product for customers in Ho Chi Minh City and Hanoi, and 500,000 VND/product for customers in other areas. The exact fee will be communicated based on the specific address.