The Cardellini Center Jaw Clamp has the fixed jaw at the CENTER of the shaft, at the base of the baby pin. It requires a little more space to clamp on than the end jaw does, but it provides a more stable attachment because the load on the baby pin is always close to the jaws. This clamp is less likely to rotate on smooth round tubing.
The Cardellini Center Jaw Clamp makes it possible to slip the clamp into tight spaces (for example: when hanging a light from a ceiling pipe). It also works best in situations where you are holding something with the clamp and putting the pin into a stand. (For example: goal posts, branches, mirrors, bounce cards, or for bracing the camera).