Thank you for viewing. This is a masterpiece backpack from Arc'teryx, designed for climbing and alpine use. I am selling it because I haven't had a chance to use it after purchasing it. Features of the Alpha FL 45 This is a masterpiece backpack based on the "Fast & Light" concept for climbing and alpine use. • Capacity: Normally 33L, but can be expanded to a maximum of 45L by extending the roll-top. • Weight: Approximately 650g-680g, incredibly light for a 45L class. • Waterproofing: Features AC² (Advanced Composite Construction) technology and seam-sealed construction, boasting extremely high waterproofness.