This is a Super Clever & Unusual Rope Effect!

The magician shows a piece of rope with a regular knot tied in themiddle of the rope.

He blows on the knot and the knot falls off! 

And as the spectator goes to pick up the knot the performer states "just Watch... and very visually, the knot reappears back on the middle of the rope

 

Instant Magic! 
Funny!
East to do! 
Great for All Venues.