The Jobu Design NX4 Surefoot Lensplate (7") is designed to safely mount and secure larger telephotos, such as a 400 mm f/2.8, 500mm f/4, 600mm f/4 and other similar lenses, to your tripod. It features 3 mounting screws for achieving multiple fit options on larger lenses, a double-dovetail profile (for using quick release flash brackets) and it's compatible with all other North American Arca-Swiss-style lensplates. This plate is functionally identical to the NX3 5.5" plate, but is quite long, enabling terrific balance adjusment.
Pick a plate that is 1" longer than the mounting-foot on your lens to allow enough room for a flash bracket with quick release to be added. Most medium to large lenses use 2 or more mounting screws.