The Lens Plate for Canon EF 100-400mm f/4.5-5.6L IS II USM Lens from Jobu Design has been custom designed to attach directly to the bottom of the lens foot, and securely lock into place with the built-in pin-and-block on the top of the plate. The pin-and-block goes into the existing holes on the bottom of the lens foot and prevents the plate from twisting.
The Lens Plate is compatible with most Arca-type compatible clamps, and the double dovetail lets Arca-type compatible accessories attach to the bottom or top of the foot. The lens plate is made from 6061-T6 aluminum, which has been hard anodized with a tumble deburred finish, making the foot resistant against scratches and scuffs. Located on the bottom of the foot are two safety stops, which prevent you from accidentally pulling the lens when the ball head clamp is partially open.