COMPOSITION. Main fabric: 90% Polyester cationic / 10% Polyurethane. Lining: 88% Polyester cationic / 12% Polyurethane GUARANTEE: Our Quechua hiking backpacks are guaranteed for 10 years. VOLUME. The volume of each backpack is measured using a standardized method: we fill the main compartment as well as each pocket with little balls. Then we empty these balls into a graduated container, which gives the equivalent volume in liters. TO ADJUST. 1 - Loosen all the straps (straps, hip belt, load adjuster straps). 2 - Put the backpack on. 3 -Tighten the shoulder straps. 4 - Adjust the load adjuster straps as needed. HOW TO PACK BACKPACK. Place heavy equipment at the bottom. Pack your clothes around these items. Keep a rainproof jacket and fleece close at hand. Place small items for daily use (sunblock, map, glasses, etc.) in the pockets. If carrying a hydration pack (water bladder), this should be placed in its special pocket along the back. The water bottle goes in the external water pockets provided for this purpose. LABORATORY TESTING. We carry out laboratory tests to validate all component parts: fabric, buckles, straps, foam and zippers. For example, for fabric: resistance to wear, tearing, colorfastness under UV rays, washing, waterproofing. A final test on the finished product simulates the kind of treatment to which it will be subjected over several years, to assess the strength of the assembly: the backpack is weighted, then placed on a dummy, which then reproduces the movement of fast walking over thousands of cycles. PRODUCT TESTING. It's in France, at the foot of Mont Blanc, that our design team conceives, creates and designs Quechua products. We test them in the field with other hikers to ensure their comfort and resistance. Brittany, Corsica ... We visit as many trails as possible, in all weathers. Moments rich in discussion, which is precious for us to get your feedback and plan our future collections!