This is a mounting bracket to mount a mini PVR commonly used for PVR base stations. It is sold by popular suppliers such Ready Made RC.

There are 2 versions available. One without and one with supports generated by MeshMixer. They look funky but they work well and remove easily.

I have an updated version with thicker retainer arms available now. Still, do not overextend them as they will break. Perhaps printing with ABS would give more flexibility.