One was a good fit, the other was too tight to fit on my camera.
I ordered two, one for a Sony FS7 and one for a Sony A7s. One of the adapters was tight, but firm and solid. The other was WAY to tight. I had to sand and file down the flanges to even get it on, and I had to sand and file the EF mount side as well (I unscrewed the mount and filed the back-side where the springs are) to get it to fit. Still a little tight, but I imagine with time it will be better.