The plate is for using a Gitzo Systematic series 3 or 4 Tripod with industrial transits, Lasers and other large tools for precise work.  Also  for some Rifle shooting applications (Check the size and thread of your MOUNT). The stainless steel mount stud is universal for many types of connectors.   Can be used in industrial or hunting applications.  The black Aluminum oversize plate is solid and precisely machined to for the current GITZO systematic series 3 and 4 legs WITH the locking channel on the newest versions.  Thanks