REALLY LIGHT WEIGHT (4 oz) and Roomy (16 Liter). Perfect for day trips, vacation, travel, day hikes, school, camping and shopping. 18*9 Inch WATER-RESISTANT & DURABLE: The backpack is made from highly rip and water-resistant CORDURA fabric, which provides strength and long-lasting performance, with minimal weight. We use durable 2-way Abrasion Resistant YKK Metal Zippers across the backpack. COMFORTABLE. Breathable mesh shoulder straps help relieve the stress from your shoulder. The length of the shoulder straps is adjustable. SMALL TILL YOU OPEN IT. Easy to folds up into small pocket (Sandwich size). You would LOVE that you can throw it in your suitcase, purse or car and have an extra bag without it taking up space. AIRPORT HERO: The Secret of Never Paying Overweight Fee! Simply unfold from your luggage and use it as a carry on for your excess baggage. Warranty: Our Promise-lifetime warranty-Exchange, return, whatever it takes.