J91 is the ACRONYM J58's bigger badder brother. Sharing the same modular, lightweight, exceedingly comfortable dna, but cut to fit over a broader section of layers and body shapes. The outstanding properties of PrimaLoft® insulation and WINDSTOPPER® shell make it formidable as both a component piece or a jacket on its own. Category defining modular insulation and lots of zippers. PrimaLoft® insulation is designed to regulate comfort levels during intense activity while offering uncompromising performance in all conditions. Combined with 2 layer Gore Windstopper®, for incredibly soft, warm and light, and protection. Specifically designed to layer underneath WIDE fit ACRONYM shells, but can compress down to be worn under STRAIGHT fit shells. Can also be worn over top of PROFILE fit items.