The Idu Light jacket uses Primaloft Gold Cross Core Aerogel insulating fiber. The airgel included in this fiber is the best currently known insulation material in relation to weight. - Windproof main material (recycled ripstop polyester, 39g/m²), lining made of recycled polyester - The elastic panels improve freedom of movement and let a little air through - Top-quality Primaloft insulating fiber, warm for its weight, 40g/m² - One zippered chest pocket and two open hand pockets - There is a wind strip under the main zipper and a collar to protect the chin from the zipper - Hem adjustment cord The surface fabric is impregnated to make it slightly water repellent without the use of PFC compounds. The surface fabric and insulating fiber are bluesign approved.