This is ANSI Class 2 Compliant. Made with ultra lightweight 3.7oz Micromesh Polyester. The micromesh"s breathability permits movement of air around the body, keeping you cool and comfortable. As a performance fabric, it wicks away moisture 3x faster than cotton. Our High Visibility Shirt is the longest wearing and lightest weight t-shirt on the market, featuring 75 wash certified reflective. In addition, the 3M™ Scotchlite™ Reflective Material – 5510 Comfort Trim adds extra comfort and does not buckle or rub like sewn on reflective tape.