What device is used to create friction on the rope for a controlled rappel or lowering?

A descender is specifically designed to create friction on the rope, which allows for controlled rappelling or lowering. When using a descender, the operator can adjust the amount of friction applied to the rope to control their descent speed. The design of descenders often includes features that lock the rope in place if needed, providing an additional level of safety during a rappel or when lowering a rescuer or victim.

Other devices mentioned serve different functions. A pulley typically aids in redirecting force and can reduce effort during lifting or hauling but does not inherently provide friction for controlled descent. A rope grab is mainly used for safety and can grab the rope under certain tensions, but it isn't primarily for controlled rappelling; it functions more as a backup mechanism. A rigging plate is used to organize and distribute loads across multiple attachment points but does not create friction on the rope in the way a descender does.