Buy from Amazon.co.uk : http://www.amazon.co.uk/gp/product/B008DZXWPY?tag=1001consej026-21

Nike Boy's N.E.T. UV Polo Shirt - White/Black X-Small

Dri-fit uv fabric to help keep you dry and comfortable while protecting against uv rays
Flat-seam construction to minimize irritation caused by chafing
Fold-over collar and button placket for versatility and classic polo styling
Side panels for mobility
Taped seams for durability and style