This is ANSI Class 3 Compliant. Made with lightweight 4.1 oz Birdseye Knit Polyester. It feels butter soft on the inside, yet is work-wear durable. It features a rib knit collar and 3-buttoned placket for a professional appearance. The performance fabric wicks away moisture 3 times faster than cotton. Our High Visibility Shirt is compliant to ANSI/ ISEA Class 3 for increased conspicuity.