a climber's fall, is marginal because of both their low breaking strength and their tiny surface area (the HB 0 measures about 4 x 7 x 2.5 mm) in contact with the rock, though this can be offset if several are placed at a time. Other names used include RPs (the brand name of the first commercially available micronuts) and brassies. They are available from several manufacturers in a variety of styles.

British climbers in the 1950s and 1960s were the first to use nuts as climbing protection. In addition to using pitons,