You’ll need the barrel nuts (or whatever they are called) that go on the ends of the kevlar cable as well.
I’ve got one coming from KS under warranty. The string in my Lev is a little too long (it has some slack in it), so the hydraulic valve won’t open completely. This means that I can’t compress the post very fast, and it extends slower as well.
I took the bottom cap off, loosened the set screw that holds the barrel nut, and tried to remove the slack from the string. It wouldn’t budge. There is some sort of plastic bit under the set screw that holds the line in place, so it looks like you need new hardware each time.
Service video here that shows how to replace it.