Warmth where you need it most. The Jack Wolfskin Men's Caribou Crossing Altis Jacket combines two high-end materials for optimal warmth and functionality. The front of the jacket is insulated with Microguard. The sleeves and back consist of Nanuk knitted fleece. This hybrid design has several benefits: You get better insulation and wind protection on the front and better breathability on the sleeves and back. This combination means the jacket can be worn on its own or as an inner jacket under your weatherproof shell, which is why it is equipped with a Regular System Zip.