For years now I have been packing around larger spools of 0x and 3x fluorocarbon in the back of my pack and I use them to tie up heavy, short streamer leaders. For years I have been putting up with these spools unraveling and making a general pack full of "wind knotts." Well last year it dawned on me that all those nice Rio tippet spools I have been throwing away have the cool little elastic bands with the gromet in them. Now I save them for my other spools that dont come with the bands and it has cleaned up my pack and caused me to waste less leader material. O.K. I'm not that bright and can't believe it took me this many years of frustration. I tried rubber bands, but they always seemed to move on the spools and release the fluorocarbon. Hope this helps.