This is a MAD ROCK AVIATOR belay device compatible with 8-11mm ropes. In addition to normal belaying, it supports belaying a second climber and rappelling. The excellent feature of this device is that the wire reduces the impact force that occurs when a climber falls (photo 2). Also, when you want to slightly loosen the rope during belaying a second climber, the small protrusion is surprisingly convenient (photo 3). The carabiner is a Black Diamond auto-locking carabiner. It is large, so it can be used with all devices. This item is being sold to clear out inventory.