A mechanical device used to create friction when belaying by putting bends in the rope. Many types of belay device exist, including ATC, stitch-plate, figure eight, gri-gri. Some belay devices may also be used as descenders. A Munter hitch can sometimes be used instead of a belay device.

A piece of equipment which you use to control the rope when belaying. Belay devices include "belay tubes" (many brands), the Figure eight, the Gri-gri, and the Sticht plate.