Galvin Green Marco Polo Shirts: The Marco Polo Shirt profits from Galvin Greens cool layering system, Ventil 8 technology, the shirts enjoy an elegant stylish design. The Ventil 8 fabric will wick moisture away from the body twice as fast as ordinary Polyester shirts, and benefits from 20+ UV protection. Ventil 8 is technology that Galvin Green use in their layering concept; Ventil 8 fabric is amazingly breathable and its moisture-wicking properties are excellent.