The Tilta PL Mount Lens Adapter Support for Sony a1 Half Cage (Black) connects to the front of the Half Camera Cage for Sony a1 and supports multiple E to PL Lens Mount Adapters via a 1/4″ connection.
This provides an additional point of contact between your cage and lens adapter which creates a more secure connection.
This helps to limit any unwanted lens shifting that could be caused by your follow focus system.