Mammut Assist Belay Resistor Gold One Size. The lightweight device attaches to the first quickdraw and increases rope friction allowing a lighter belayer to catch and hold a heavier lead climber's weight. Thanks to the patented cam construction only a fall or lowering motion activates the resistance and the rope is never blocked completely. Instead the device facilitates smooth handling and soft catches allowing it to be used effectively for dynamic belaying. Take on new routes with confidence with the Mammut Assist Belay Resistor. Specifications for Mammut Assist Belay Resistor: Manufacturer: Mammut Size: One Size Color: Gold Package Contents: Mammut Assist Belay Resistor Mammut 2040-03050-7041-1: Assist Belay Resistor Gold One Size