Heya,
I have a link to our store in which we sell a few accessories that has just a tad more info on them (Link Deleted, no longer valid) The actual coil is a heavy plastic, and stretches to about 5 feet. They're a nice commercially made rod leash, and I use them on my rods as well as carry them in our store. If you're thinking of making your own rod leashes, having one may be a good way to see a premade one and see what about the design you may want to change for your own tastes. Some anglers really like the coil cord, and others hate them. We have 1 left in stock and when it's gone, it be gone. If you want more, I suggest
http://www.kayakfishingstuff.com as they also carry them in quantity. Other places also carry them, but the guys at KFS have always supported our website, and been decent and professional whenever we have talked with eachother, so I recommend them as well. Hope this helps,
Perry