The dual layer cotton back gives the wearer the feel of cotton and breathability of "Quick Dry” and provides more comfort than polyester. Dual layer cotton also decreases irritation and does not have a strong fabric scent compared to polyester material. The hi-visibility polyester outer layer holds color longer and is CSA compliant. Dual chest strap for ID badge, cell or radio. Velcro sealed chest pocket. Ultraviolet Protection Factor (UPF) of 50+. Blocks 98% of UV radiation from passing through the shirt. Dual chest straps for ID Badge/Cell/Radio. Velcro sealed chest pocket. Green & orange are fully compliant with CSA Z96-09 Class 2 Level 2 & ANSI/ISEA 107-2010 Class 3 Level 2, and become CSA Z96-09 Class 3 when combined with the correct arm and leg bands. Navy is fully compliant with CSA Z96-09 Class 1 Level 2 & ANSI/ISEA 107-2010 Class 1 Level 2. Sold by each.