[rvitko]

That is the upper bearing, It is probably at the bottom of the impeller well. It normally stays down there but it is good preventitive maintanence to remove it and clean it as it is critical to the cooling and lubrication, the water moves down through the hole in the magnet through the bearing and then comes up along the side of the magnet and out. If this piece gets clogged with calcium the pump builds up calcium faster due to insufficent cooling. A pick or screw or small needle nose can be used to remove it. I prefer a pick tool, you can buy a set at Lowes or Sears for about $7.