External System: Elastic cords on the front and webbing on the bottom can be used to secure items such as trekking poles. The bottom buckle can fix the sleeping bag and the hiking backpack has two adjustable shoulder straps at the front to store the skateboard. Adjustable strips on the sides secure items in side pockets and zippered pockets. There is an external webbing at the top. Safe & Versatile: An emergency whistle on the chest strap buckle can attract the attention of others in case of danger or emergency, ensuring your safety. The main zippered pocket has a hydration compartment and a water pipe fixing rope on the shoulder strap to keep the hydration bladder in place, so you can stay hydrated. Soft & Comfortable: The back and the shoulder straps are padded with 3D sponge, which are soft and comfortable. The mesh design is breathable to dissipate heat and prevent perspiration. There are chest straps that can be adjusted up and down, so they can adapt to a variety of body types. There is an adjustable waist belt to be able to distribute pressure. Durable & Multi-Pocket: Made of oxford fabric, it is water-resistant and wear-resistant and can adapt to outdoor environments. with the SBS zipper, it is sturdy and smooth. There are multiple pockets, one front zippered pocket, one main zippered pocket, two side pockets, and a top pocket to help you keep things organized. Multi-Purpose: This 30L multi-purpose outdoor backpack weights only 0.54kg, which is lightweight and durable. It's suitable for outdoor sports such as camping, hiking, climbing, running, etc., and is also suitable for work and school. The look is stylish and adds color to your outdoor workouts. ASIN B0DPQBYQXV Size 30L Color Blue Pattern Solid Brand Name Outplea Strap Type Shoulder Strap Manufacturer outplea Style Number ZQ0085B Material Type Polyester Product Style Daypack Backpacks Outer Material Polyester Storage Volume 30 Liters Lining Description Polyester Apparel Closure Type Zipper Age Range Description Adult Water Resistance Level Water Resistant Manufacturer Part Number ZQ0085B Item Dimensions D x W x H 7.5 D x 11 W x 19.3 H Product Care Instructions Hand Wash Only Recommended Uses For Product Sport Other Special Features of the Product Adjustable, Elastic Band, Fit for Skateboard, Lightweight, Waterproof