XM-TANGLE FREE REG DOUBLE SWIVEL 10'- The Tangle Free™, double-swivel leash helps avoid the cord wrapping around your leg or foot before taking off on a wave. This is because there is a slider, which is simply a small weight that moves on the cord, so that while you’re sitting in the line-up, it pulls the cord down, thus keeping it away from your foot, so you’re less likely to step on it!