It is a chain of slipknots that will come either come undone when both ends are pulled simultaneously or stay together when the end is knotted
(This is my first instructable so be vicious with what i could improve)
Step 1: Materials
Step 2: Beginning The Chain
Then using the long side make a bend near the loop
Next pass the bend through the loop and pull and then pull it tight creating another loop
(to tighten pull on the side that is not loos in this case the left one)
Now make another bend in the long part of the rop and pass it through the loop you just created then tighten it.
Step 3: Continuing The Chain
Step 4: Undoing the "Slip Chain"
and the chain will come apart
(if the chain is pulled overly tight it may be a little harder to pull apart)
Step 5: Locking The Chain
Instead of making a bend and passing it through the loop
take the end of the rope and pass it through the loop