100% Cotton The lightweight 80 grams Smart 2.0 is easy to operate and has no moving parts or levers. As it operates according to the tube principle, the Smart 2.0 is therefore suitable for both lead climbing and top rope climbing. In the event of a fall, the Smart 2.0 blocks the climbing rope, with the newly developed high-performance brake insert interacting with the belay carabiner. It therefore offers the belayer optimal support and signifi cantly improved safety. Mammut recommends use of the Smart HMS for the Smart 2.0. It is suitable for rope diameters from 8.7 to 10.5 mm.