A slat’s profile has to do with its shape along the shortest edge. Most profiles are named for the part of the shape between the the top and bottom eyes such as “Flat,” “Single Crown,” and “Double Crown.” Their names can also include the height dimension of the profile such as two inch, three inch,or four inch. Some slats are doubled up (back to back) so that their profiles form a channel that is filled with thermal foam, such as a “Double Insulated Flat Slat”.