Molnia 50L expandable travel backpack. Bought from Amazon. Took on 2 separate trips as my carryon; a 2 week trip and a 3.5 week trip. Fit on all my flights in the overhead bin. Dimensions: 21.3*7.87（+2）*13.8 inches, Weight: 3.3lbs. Laptop compartment can hold both a 17.3-inch laptop and a 12.9-inch iPad