Hejnar Photo Arca Type Foot Replacement for Canon EF 400mm F/2.8L-is - Made in U.S.A

Replacement foot for: Canon EF 400mm F/2.8L-IS Double-dovetail design allows for dual clamping surfaces on rail To remove the Canon foot, use the M3 hex key tool that comes with the H110 to completely remove the four Canon mounting screws. To install the H110, use the four original Canon screws and secure the foot to the lens collar. If your mounting screws loosen over time, consider using Loctite 242 for security. 1/4-20 and 3/8-16 tapped holes. Two safety stops. This prevents free fall when the clamp is not fully closed (M3 screws)