Material: The canvas bag is made of wear-resistant Oxford fabric, the main compartment opens with double zipper closure. Reinforcement strap. Comfortable grip carrying handle. Adjustable double shoulder straps, use it as a backpack. 360 Swivel Wheels: 4 stable and low-noise 360-degree swivel wheels can make your ride more comfortable. (swivel wheel is detachable) Foldable: Foldable design, easy to carry, save space, you can put it in your trunk or suitcase for easy use. Expandable: large size is about 20.86 x 18.11 x 11.81 inches, expands to 24.80 x 18.11 x 11.81 inches; Small size is 19.68 x 16.14 x 10.23 inches, expands to 23.62 x 16.14 inches, large. capacity, can hold the items you need when you leave. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.