Hey cruiser - its for running 2 leggy strings on the one legrope to give you extra security in big surf. Not really necessary as leggies tend to give way before the strings or leash plugs do. If your next question is "which one should I use" - being a goofy footer I have always used the right hand one = no particular reason, just feels right.
Also the board will pull to one side if you pull it back. So you can set it to come back to your prefered side to get back on. Or run 2 ropes for bigger stuff.
