Fit C300 canon camera and let you use the mate box as the camera stand close to the 15mm rail rod
Here are others details from Redrock website:
Completes the Canon EOS C300 camera – by providing the necessary baseplate and cage can stay permanently on the C300 even while accessing any of the camera’s features or attaching accessories like the C300 removable handgrip. Mounting points everywhere The ultraCage™ was designed specifically to deliver this without getting in the way of accessing all the camera’s features. Infinitely expandable – simple and compact, or full featured and ready for the fischer dolly, studio or handheld. Redrock’s solutions have your C300 covered, Ready to go for large lenses – ultraCage baseplate already has the correct height and mounting points for adding 15mm studio or 19mm rails to support big cinema lenses from Canon, Cooke, and others.
It comes with a RedRockmicro micro-mount Cold Shoe to put the C300 monitor screen on it.
You will need to exchange the Canon plate under the camera if you want to use both screw on the bottom.