Specification 15.6'' travel laptop backpack: Dimensions: 18 x 12 x 7.8 inches； Item Weight: 1.68 pounds； Capacity: 28L； Seperate laptop compartment fits 15.6 inch laptop; 17'' travel laptop backpack: Dimensions: 19 x 13.8 x 7.8 inches； Item Weight: 2 pounds； Capacity: 35L； Seperate laptop compartment fits 17 inch laptop; TSA-Friendly function: laptop compartment can open 90-180 degree; 18.4‘’ travel laptop backpack： Dimensions: 9.8 x 15.7 x 21.2 inches； Item Weight: 2.23 pounds； Capacity: 54L； Seperate laptop compartment fit 18 inch laptop; TSA-Friendly function: laptop compartment can open 90-180 degree; Features Spacious packing section Multiple front pockets Pen/key organization Padded ventilated back Adjustable shoulder straps Cushioned top handle Luggage strap compatible Hidden anti-theft pocket Air travel friendly Internal charging cable Water-resistant polyester fabric