This is the typically flimsy plastic bottle that generic aspirin comes in. It was knotted for the same reason mountain climbers are reported to give for why they climb — because it was there. It has no other virtue commending it for knot work. The two white rings and the thin ring just under the lid flange are all Spanish Ring knots. The main knot is a 13 Lead X 4 Bight Turk’s Head knot, doubled. What amazed me was how much the knots strengthened the bottle. It no longer “oil cans” at the slightest touch, and it just feels much firmer. I did not expect so much change.