This is NOT the Ultralight model. And this model, the BD850L-SET, appears to have been recently discontinued.This L-Plate bracket is modular. You can remove the side portion of the bracket, and work with the bottom plate only. However, you should probably install the attaching screw if you intend to keep the unit whole. Having the screw installed provides a much more secure connection between the l-plate bracket and the D850. It's very solidly built, and has terrific fit and finish.
Nab yourself a good deal! 1/4-20 threaded accessory mounting socket.