The swivel allows complete rotation of the strobe head.
This allows you to place the infrared receiver at any angle towards the camera for more reliable triggering.
The back flaps of the FourSquare should be open to allow a better line of sight.
If you will be using the Pocket Wizard Flex TT5 and the FourSquare Bank Light, you can use a swivel to raise the Flex TT5 unit in height to clear the poles in the Bank Light and will allow for limited rotation of the Speedlight / FlexTT5 unit.
L: 1.06in / 2.70cm
W: .75in / 1.91cm
H: .875in / 2.22cm
.9oz / 28g
1 360 Degree Swivel
1 Nylon Thumb Screw
1 Stainless Thumb Screw