The Q-Release allows you to mount the Zacuto shoulder pad underneath your camera for better counter-balance when using a Depth-of-field adapter or camera package lengths up to 36 inches. It allows you to move the center of gravity forward. It also has a handy quick release that allows you to quickly mount and un-mount the shoulder pad.
Note: Zacuto shoulder pad sold separately
More information about Zacuto Products (Link to Zacuto Website)