Hejnar Lens Cradle for Fujifilm 100-400
Recently I purchased a Hejnar replacement foot/cradle for my new Fujifilm 100-400 lens.
The Hejnar replacement foot uses the Arca-Swiss style mounting system. Fujifilm lens uses the traditional tripod mounting screw system. I looked at several possibilities and found that the Hejnar meet my needs – plus it is designed and manufactured in the United States by a photographer in the Midwest. 
I mounted the footer yesterday afternoon and this thing is rock-solid. The Arca-Swiss plate slides right into my Acra-Tech Wimberly, Really Right Stuff and Arca-Swiss Cube heads.
Not affiliated with the owner, but pleased with the product and thought I would share a bit of information about the company. They make all sorts of camera, lens plates, replacement feet and panoramic accessories. Basically, a one-person shop who makes quality goods.
Hejnar Photo Store is a small company focused on products designed for photographers by photographers.