Kong Classic Figure 8, Bright

This device is also useful as a stitch plate; by threading a bight of the rope through the bottom hole and clipping into it with a carabiner, one can belay their partner while climbing. 

*NOTE: Figure 8 descenders tend to violently twist and kink the rope during rappels, exacerbating the wear on the rope, especially between the core and the sheath of the rope.  This twisting and kinking suggests early retirement of the rope.  Likewise, these descenders are very small and do not dissipate heat very well.  High speed rappels are discouraged with Figure 8 descenders.