1. Double-layer zipper, explosion-proof zipper, anti-theft & longer life time & lifetime warranty

2. Classic version 70*200D Nylon Fabric & Expandable version 900D Guzhi Nylon Fabric, wear-resistant & scratch-resistant; anti-Freeze & waterproof, with environmentally friendly fabric, no peculiar smell;

3. Classic version with 30L large capacity design & Expandable version with 40L large capacity & Muti-functional pockets: main compartment, independent laptop compartment, back anti-theft hidden pocket, ect ;

4. Other convenient details design, such as reinforced shoulder strap, pull rod fixing belt design, comfortable handle, curved shoulder strap; honeycomb breathable air cushion, convenient headphone jack, card pocket on shoulder strap ect.