This is a mount for this board: https://github.com/ed7coyne/xt30_dist_board to a rack with standard rack-hole spacing. This mounts it to the side of the rack (see photo).

That board is a xt30 connector power distribution board, see github for details.

Model is here for tweaking: https://cad.onshape.com/documents/10b6675447a121e0ae1a43e0/w/49771f69cc01ef211a75982c/e/0b423fe340418d72e9f6bb51?renderMode=0&uiState=67e97274b9e85c40c4ec1e29