The E-Mount to Sony FZ Mount Adapter for Fujinon MK Zoom Lenses from MFT Services is made from aircraft-grade aluminum and it replaces the existing Sony E-mount in the MK lenses. To attach it, remove the four screws on the existing mount, gently remove the mount, and then secure this adapter with those same four screws. Line it up with the location pin for proper positioning, and check the lens' back focus to see if it needs any minor adjustment. Any shims under the existing mount should be left in place.