I have a captains chair mount I need to get rid of. Not sure what it is for I discovered it when I took out some old carpet. It is approximately 12" square, and has "key hole" slots in it. I am assuming that it is some kind of removable (chair) type base. Not sure what it is worth, don't want to send it to the scrap yard yet. If anyone is interested, I can text you photo's. Thanks...kt