Post with transom mount goes on your trailer hitch. Rack with clamps mounts to roof. Gutter mount for bracket shown or crossbar like Thule or Yakima rack needed to set boat on. You put boat transom on transom mount and tighten clamps then lift bow and swing around to sit on roof rack. Rack has clamps to hold boat to rack. Allows one person to load a small boat. $30 or best offer.