Jackson Safety Winter Liner 325 Ultra (14499), Universal Size, 3 Units / Case 3 Jackson Safety Winter Liner 325 Ultra / Case For cold weather environments (0 to -20F) and can be worn over hearing products (ear plugs or hearing protection) Top section is flame retardant, bottom section is flame resistant: Nape piece closes with two buttons Detachable bottom section is double layered, heavy spun polyester; Cotton twill top shell with polyester fleece; Double nylon knit bottom shell Meets 16 CFR 1610, Class 1