Lens Support Adapter (FS7) is designed to attach to the Top Plate (FS7) and clamp onto the E-Mount To PL Mount Pro when attaching to Sony PXW-FS7 camera. This is perfect for previous customers who purchased the E-Mount To PL Mount Pro (A7s) and are upgrading to FS7. Loosen the support ring thumbscrew to quickly remove the mount and install another adapter. We are working on additional E-Mount to Canon, Nikon, etc. that will be available in the near future and will integrate with this same ring support.