Pls reference the bag outer dimension ( length x width x thickness ) before your order it. 13.3 inch bag : Outer dimension 35.0 x 25.5 x 3.5 cm , Inner dimension : 33.0 x 23.0 x 3 cm 14 inch bag : Outer dimension 38.5 x 27.0 x 4.5 cm , Inner dimension : 37.0 x 26.0 x 4 cm 15.4 inch bag : Outer dimension 39.0 x 27.5 x 4.5 cm , Inner dimension : 37.5 x 26.5 x 4 cm 15.6 inch bag : Outer dimension 42.0 x 30.0 x 4.5 cm , Inner dimension : 39.5 x 28.5 x 4 cm 13.3 inch bag is not good fit for macbook all 13 inch, For macbook new 13.3 inch, own thin screen frame, the laptop outer length is just 304 mm, but for macbook old 13.3 inch, the laptop outer length is 325 mm. 13.3 inch bag is just can perfect fit for macbook old 13.3 inch ( laptop length 325 mm), 13.3 inch bag is big for macbook new 13.3 inch (laptop length is 304 mm) ( Such as : model A1706, A1708, A1932, A1989, A2159 ), pls make order if you can accept big bag. Pls remember contact with us if you cann't make sure which size bag is good for you laptop. Each bag have been add shoudler strap. Kind remindly, the bag bag material, it looks like PU leather material, but actually, it is n't PU leather. The bag material is more durable than PU leather, it canvas with surface waterproof coating.