Carhartt's flame-resistant work-dry lightweight twill shirt is a comfortable choice on warmer days. Offering an original fit and made of 6-ounce, FR twill- 88 percent cotton/12 percent high-tenacity nylon, this shirt provides a button-down collar with button closure, FR melamine buttons throughout, two chest pockets with flaps and button closures, extended sleeve plackets with two-button adjustable cuffs, has the Carhartt FR and NFPA 2112/HRC 2 labels sewn on left pocket and it meets the performance requirements of NFPA 70E standards and is UL classified to NFPA 2112.NOTE: If your chest and/or waist measurement falls between sizes, buy the larger sizes.