Fleece isn't fussy, so we like the Trollveggen Thermal Pro Vest as a winter mid-layer or outer layer. Norrona's warmest, most durable vest is made with 295-weight Polartec Thermal Pro fleece, which is durable, breathable, insulates when wet, and offers good warmth for the weight. That makes it a reliable insulation piece in all weather, and it's also made from recycled materials, reducing our resource consumption for a lower environmental footprint than most fleeces.