550 Cord Spool

Paracord 550 is like duct tape, it has a zillion uses and can help you fix a lot of stuff. I always carry about 30' (about 10 meters) or 550 cord in my ruck, you never when you'll need it.

My friend James built his own cord spool.

I think they are great. Follow the link on top if this post for more information about this.