Premium Material -Motorcycle bag is made of 1680D Oxford cloth + waterproof cloth +EVA. External 1680D Oxford cloth tear resistance to provide excellent durability and long life. Waterproof material and rain cover you can use it on rainy day. Linner with oxford cloth soft and breathable.Reflective Design -Reflective straps on the front of backpack for safe riding at night,expandable for a larger volume for holding helmet.Two-way zipper design, easy to take items from all angles.Size Design -Size: 16.9"L x 11.8"W x 6.7"H Standard / 16.9"L x 11.8"W x 11.8"H Expanded Weight: 1.1KG. This bag has an extension function to expand the capacity of the backpack.Practicality And Versatility -A good bag to store your Helmets, Cycling Wears, Gloves, Computer, Shoes, etc.Also features a expandable bottom section to enlarge storage space.Multifunctional Usage -The motorcycle seat bag fits most of the motorcycle, it can also be used as a backpack.