Our Long Sleeve T-shirt features our latest technology development called ZnO SUNTECT®. These versatile long sleeve sun screen shirts blend the comfort of natural cotton with the sensibility of viscose from bamboo and the therapeutic benefits of zinc oxide, making them perfect for every activity under the sun! ZnO SUNTECT® embeds millions of tiny particles of zinc oxide — the same ingredient that is used to block UVA & UVB in better sunscreens and to treat mild skin irritations and burns — into every fiber. These ZnO particles cannot wash or wear out. Great range of colors – buy several for year round use!