Material - 600 D Polyester construction. Main compartment opens with twin zipper closure. Reinforcing strap. Three levels fordable. Comfort-grip carry handle. Adjustable and Removable shoulder strap. Two front pockets for last-minute storage. Collapses to 4" D. when not in use. 4 of sturdy 360° swivel wheels for easy rolling. Bag body can be expanded by zippers from 15" to 22.5" to 30" high. Dimension Constructed: 18" L x 12" W x 15" H. Dimension Expand half way: 18" L x 12" W x 22.5" H (First zipper opened). Dimension Expand all the way: 18" L x 12" W x 30" H (Both zippers opened). Weight: 3.5 lbs.