Posi-Slot™ means that once its in it stays in.
No mistakes.

Posi-Slot™ takes all types of elastic cord and rope.

What makes Posi-Slot™ unique:

If you don't get the cord locked into the slot correctly then as soon as you start to
put any tension on the cord the end flicks up and you know to stop. With all
other elastic cord connectors there is no way to know if the cord is in securely and
worse it will normally come flying out after you have put a lot of tension on it.

Posi-Slot™ is the only elastic cord connector which tells you the cord
is secure BEFORE you put enough tension on it to be dangerous.