 How to differentiate Cat5e, Cat6, and Cat6a cabling? The quickest way to see the difference between the cables is on the outer sheath of the cable. The sheath contains codes and markings to clarify what type of cable it is. In some cases, it may be a part code that is easily searched for clarification. Telling the difference between Cat5e and Cat6 or Cat6a is visually straightforward. The Cat6 versions will have a plastic central divider whereas the Cat5e will not. However, the visual look of Cat6 and Cat6a is quite similar. One visual difference if you have both cables is that the Cat6a cable is larger in diameter and size. It will also feel physically stiffer. If you have a single cable with a central divider and you are unsure of the cable type then the outer cable sheath markings are the best way to tell.