Jack Wolfskin Womens ACS Hike 22 Pack style:1.shell: 100% polyamide; 2.shell: 100% polyester; lining: 100% polyester Imported 7.87" high 11.02" wide Acs: flexible, Classic suspension system with spacers for effective back ventilation and specially shaped, ergonomic shoulder straps Adjustable chest strap with signal whistle Trekking pole attachment Compression straps on sides Reflective detailing