Here are instructions for how to belay with an ATC. The ATC, or Air Traffic Controller, is the most common type of the belay devices in the present, replacing the classic Super 8 as the friction tool of choice for most climbers. Different types of ATCÂ´s can be found in the market, some of them quite sophisticated. An Anchor, that could be a fixed one in the case of top roping or a gym wall, or a temporary one when lead climbing. 2  A rope, long enough to connect both sportsmen through the anchor. 3  An ATC device. 4  A locking carabiner. 5  Tie the climber to one end of the rope, using a figure eight double loop knot to the harness.
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