The Black Diamond twin axle design used on the Camalot C4 range allows retraction of larger cam lobes to give a much wider expansion range than normal single axle cams. So you need to carry fewer cams to cover a wider size of cracks & placements. The C4s are lightweight & very slick to use, even with gloves on, making them the worlds number one camming device. Go on, treat yourself. Double-axle design offers widest range for each cam unit C-Loop continuous cable stem design is strong & durable Color-coded for easy identification & wide range of sizes