Can anyone explain in laymans terms what a Kleins bottle is . I have encountered the definition that it is a non orientable surface , that it is a 2 dimensional manifold in 4 dimensions. I dont have a clue what a non orientable surface is , or what a manifold is . I also dont have any idea how to think in 4 dimensions. Could anyone help here . Maybe if its not possible to expain in simple terms , you could provide links from where I can learn the math required.