Gravity Boot [Level 7]
Notes and Resources:
This tie was invented by Jack Elfrink, one of the preeminent knot geeks in the bondage community back in the early 2000s. His original method used a clever knot at the end unique to this tie; but that tutorial is no longer available, and it's more common now to finish it like a standard column tie. This video shows a version finished with a Somerville Bowline, which appears to be Jack approved.
There's also an old Kink Academy video of me tying this.