【Large Capacity & Ultralight】40+5L (45L) and 60+5L (65L) options. Weighs only 2.33 lbs, dimensions 22.05 x 10.24 x 7.09 inches. Multiple pockets, hydration compatible, built-in rain cover. Ideal for 4-season mountaineering, camping, and long trips. 【Ergonomic & Breathable】Padded back panel and thickened shoulder straps reduce pressure. 3D mesh cushion provides ventilation, preventing sweat buildup during long hikes. 【Versatile Storage】Compression straps secure trekking poles, sleeping bags, tents. Independent rear pocket for shoes or dirty gear. Main compartment holds clothes, bottles, essentials. 【Durable 420D Fabric】High-strength tear-resistant nylon, scratch and wear resistant. Supports up to 11KG load. Water-repellent coating; rain cover stored in bottom pocket. 【Multi-Scene Use】Lightweight and compact for mountaineering, hiking, camping, travel, commuting, school, gym, emergency. Balanced weight-bearing reduces fatigue.