This 2020 V-Slot Stiff Arm Phone Mount was created to allow me to connect my cell phone and ring light to my 3D printer. The version shown in the photo was the prototype. It is meant for you to slide the slotted end into the v-slot of the rail. There will be a nice snug fit as to not require any screws. The version of the file also has the holes made to allow for zip ties to help keep your cord(s) nice and neat.
The author hasn't provided the model origin yet.