Colorful Designer Button Up ShirtComposition: Polyester Package includes 6 pieces. Size tags are in European standard. Please see the size chart available in the product photos. 2 pcs S M 2 pcs L XL 2 pcs 2XL 3XL To accommodate your US customers and align with European sizing standards, you can make the following adjustments: For US customers who typically wear XS S, you can provide them with Europe S M size. For US customers who usually wear M L, you can offer them Europe L XL size.