Specification: Net weight: S: 0.5kg; M: 0.6g ;L: 0.7kg Color：Black Materlal:Oxford Lining: Polyester Fabric Adjustable Shoulder Strap: you can adjust the shoulder strap as you like. Superior Material: it made of quality waterproof oxford fabric, you dont need to sware it get wet on the rain. 1: PVC fabric + Oxford waterproof fabric, wear-resistant, scratch-resistant and water-repellent 2: The anti-theft zipper on the back can hold valuables 3: Widen the shoulder straps to reduce shoulder pressure 4: Upgraded hardware shoulder strap buckle, zipper closure is added to the main bag, and zipper pocket is added inside 5: back slip pocket 6: The compartment is equipped with a computer shockproof air cushion