The Kirk LP-53 Lens Plate is designed to take the place of the original tripod collar foot of the 500mm f/4 IS lens, and to convert the collar to make it directly compatible with Arca-type quick release clamps, without the need for additional quick release plates. Critical mass is reduced, but the original Canon design is still maintained, which allows it to still be used as a carrying handle.
Each adapter comes complete with all the necessary hardware and tools to make the conversion.
LP-53 Replacement Arca-Type Quick Release Lens Plate/Foot
Installation Tools & Screws