14-15.6 Inch: External dimensions: 16 x 11.5 x 1.5 inches, internal dimensions: 15.6 x 11 x 1.1 inches, compatible with most 14-15.6" laptop computers
13-13.5 Inch: External dimensions: 14.5 x 10.5 x 1.5 inches, internal dimensions: 14 x 10 x 1.1 inches; compatible with Surface Laptop / Surface Book, 15" Macbook Pro and Most 12" 13" Laptop Computers
12-12.9 inch: External dimensions: 13 x 9.5 x 1.25 inches, internal dimensions: 12.5 x 9 x 1 inches, compatible with Surface Pro 6 / Surface Pro 2017/Pro 4 3 2, Google Pixelbook, 13" Macbook Pro, 12" MacBook/11" MacBook Air/Apple iPad Pro, most 11" 12" Ultrabook Tablet Laptop Notebook Chromebook