*Product Capacity*before expand 30 liter cargo capacity,size 38*20*56cm, after expand expand 48liter,size 38*30*56cm *Product Material*the motorcycle backpack is made of carbon fibre,PVC/1680D Oxford.Rugged, water-resistant nylon construction with reinforced Carbon fibre PVC body and lid to hold shape even when empty.High-Density weave adjustable belt, High thickness Fully adjustable and removable no slip sternum strap, suoerior quality electroplate zipper.Padded and fully adjustable riding specific shoulder straps with quick release exit buckle. Concealed handle. Helmet Hang Buckle. *Safety *Reflective patch for additional nighttime visibility,Streamlined single shot molded exterior is water resistant and will not deform from wind shear. Shoulder gasket conforms to body and increases aerodynamics. Bolstered back foam profile increases air ventilation. Soft neck shoulder straps increase comfort while riding and will not scratch helmet exterior. *Large Capacity*The bags before expand it has 30L, after expand ,it has 48L.it can be inside full face helmet.laptop *Multifuctional* It can be used as motorcycle backpack,luggage bag,travel bag,helmet bag etc. This motorcycle backpack made with carbon fiber, waterproof Oxford cloth ,can be expand from 30Lto 48L. It can be put inside full face helmet