These Black Diamond pitons are differentiated by size number. Knifeblade #1, #2 thin (approx. 3.2mm) Thin, shallow cracks Bugaboo #3 to #6 thick (approx. 4mm~) Wide, solid cracks Knifeblades: They have very thin blades, suitable for driving into fine cracks that are only as wide as a hair. They are lightweight and compact, allowing for secure anchor construction while minimizing damage to the rock. Bugaboos: They have thicker blades than knifeblades, suitable for firmly biting into cracks and pocket-shaped gaps that have some width. They are more versatile and can handle various rock types and crack conditions. Both are traditional climbing gear made of chrome-molybdenum steel, playing an important role in ensuring the safety of climbing routes.