You display two different colored strings which
pass through two plastic blocks
You can pull either string to show that it passes through both blocks.
For example. The yellow string is at the top and the red string below.
Now pull the blocks apart completely and the yellow is at the bottom and red on top.
Slide the blocks up and down and the cords keep changing places.
The item is self working and you can repeat as often as you like.
Tags: Crazy Cords