what is this?

Hello. I am really new to this and I have this thing that was given to me when my brother in-law past away from his saltwater tank and I am not sure what is or what brand? i believe it is a protein skimmer (never seen one just from picture I have seen) and i do believe it is missing some part yet again just from looking on the web. I also have no clue what brand it is so that I can order the missing parts. Any input would be helpfull thanks!!