Paladineer Hiking Backpack Outdoor Lightweight Cycling Backpack Hiking Daypack Sport Bag What is material - Made of abrasion-resistant polyester fabric,duarable and water-resistant. What are the compartments - Main compartment with hydration reservoir sleeve, 2 zippered pockets, mesh side pockets. Something about shoulder straps - Air mesh on the shoulder straps adds extra breathability What kind of design - Versatile enough for the everyday and heavy-duty enough for the cycling, hiking, camping, etc. What's more - Helmet mesh cover included to storage your helmet