CdyBox 35KN Super 8 Belay Device Titan Figure 8 Descender for Climbing Belaying and rappelling Light Weight and Strong Material: Aluminium and Magnesium alloy forging. The Super 8 is an anodized, super-light and full-size figure 8 that works extremely well when rappelling. Its traditional shape allows the rope to smoothly flow with the perfect amount of friction for the task.