The ˜Air Traffic Controller aka the ATC was created by Black Diamond back in 1993, ushering in a new age of belaying. Since then, the ATC has gone through multiple iterations and is now a time-tested and versatile tubular belay device that provides ample friction for belaying. The ATC-Guide is Black Diamond's most versatile belay/rappel device ready for multi-pitching missions. Great handling in guide mode with an oval-ized anchor-hole, the device feeds rope and allows you to pull rope more easily. Multiple friction modes provide the optimal amount of stopping power when lowering or rappelling, and the device's guide mode lets you belay one or two seconding climbers off an anchor.