The inside spring of the electric fence jumper leads can be at the front or at the end, the difference is that:

If the spring is at the front of the electric fence jumper leads, the biting force is slightly weak, but the cable will be easily installed.
If the spring is at the back of the electric fence jumper leads, the biting force is strong, but the cable installation will be blocked by the spring.

So, normally the spring is at the front, please see the following pictures: