I got one and it has two rifle length cords. It has one 34 inch and one 30 inch. The 34 inch is really skinny and has a slot attached to it. Is this one for .17 cal rifles? The 30 inch one is thicker (probably around .200). It has two female ends. Is this one for 223/556 and larger calibers? It attaches multiple size slots to it. Just want to make sure I use the right cord. thanks

Use the cord that fits your barrel.  Then go with the proper eyelet.  If there is no appropriate adapter for your eyelet and the cord you picked, you picked the wrong one.

Read the directions.  People fuck this up all the time.  They tell you a way to place a patch on the eyelet that it will come loose before it jams in your barrel.  Ignore that rule at your own peril.

I read the directions amd used the kit a few times when out with a buddy. I am just wondering what cord. You said us the one that fits. They both do. Which one do i use?

If it fits down the barrel and is long enough to feed it through and grab the free end, it really doesn't matter.

Yes, the longer skinnier one is for .17cal rifles. Use the larger diameter cord with appropriate eyelet for your 5.56 rifles. Definitely pay attention to the way you put the patch on. Lots of people make it too large and have issues. FWIW I've never had an issue.

You'll want to use the 30 inch one that is a bit thick. The skinny one will rip as it is too small.

The .22 barrel is a very tight fit and as such you'll have to make sure you follow proper instructions. See the otis website for instructions:

http://admin08.webstorepackage.com/otisgun/virtualweb/Images//AD-2004.pdf

Warning it's a pdf but the instruction is very well written. It should have came with your otis pack. I got mine in each of the military version of the kit. I never got the skinny cord except when I bought the civilian version of the multi-caliber softpack.