The Jobu Design NX3 Surefoot Lensplate (5.5") 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 double safety-stops and a double-dovetail profile (for using quick release flash brackets), and it's compatible with all other North American Arca-Swiss-style lensplates. It also has a built-in anti-twist flange to prevent your lens from unscrewing during use. This plate is functionally identical to the NX4 7.0" lensplate, but is somewhat shorter to allow easier fit into hard travel cases.
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.