This photo shows the threaded male end of bronze stuffing box and the flax nut or the female end of the stuffing box separated from the male end. The white PVC pipe is my mock up of a fiberglass shaft log.
The rubber hose connects the bronze stuffing box to the boat and must be replaced periodically. If this rubber hose cracks, and starts leaking, it could sink your boat. Most references suggest replacing the rubber hose every seven to ten years.