This is easily inspected. The final structure forms two opposing X’s that when pulled toward each other act to tighten each other. The connection is less bulky than other bends and flows more easily over a block.
Essentially the bend is formed by tying a double overhand knot in the end of each rope with the other rope or part inside the knot. The knots are tied in opposite directions.
1. Take one running end of the rope and tie a double overhand knot.
2. Insert the other running end through the knot.
3. Make a loop around the standing part with the running end that you just inserted through the knot.
4. Loop around both standing parts once more.
5. Take the same running end and insert it through the loops from the side of the other overhand knot.
6. Dress and set the knot.
7. To tighten this bend grab both standing parts, one with each hand and pull together.
8. To loosen this bend grab both knots, one with each hand and pull apart.