Belay device

A belay device creates friction against the rope so a belayer can pay out slack as a climber ascends, hold a fall by clamping down on the brake strand, and lower a climber back to the ground under control. Most designs are variations on a tube or plate that the rope runs through in a bent path.

Standard tube style devices rely entirely on the belayer's brake hand to create that friction, while assisted-braking devices add a mechanism that helps pinch the rope during a sudden pull. Device choice also affects how smoothly you can pay out rope to a leader clipping quickdraws, how easy lowering feels, and whether the device can back up a rappel.

Learning to belay well takes hands-on practice and proper instruction from a qualified instructor or experienced climber, not just reading a guide, since brake hand position and catching technique are physical skills. When shopping, match the device to your rope diameters, since devices are rated for a specific range and perform poorly outside it.