Ultra-light design: Minimalist. Hot forged aluminum. Weight: 59g. One single device for all rope uses: Effective braking with double and twin ropes with a diameter greater than or equal to 7.5 mm. Efficient braking with single ropes with a diameter greater than or equal to 8.9 mm. Belay of the first rope, of one or two seconds and abseil descent. Independent and simultaneous two-second assurance in reverse mode. For "alternate" climbing (2 roped), you quickly switch from Reverse to the assurance of the first.Braking zones in v: Increase braking force with thin ropes. Adapt the braking force with the larger diameter ropes. Increase the locking pressure of the strings in reverse mode. Asymmetric side ribbing: Increases the braking force when the rope enters the apparatus (falling, pulley climbing and rappelling). Increases fluidity when the string leaves the apparatus (retrieve string). Unlocking hole for the device under tension: allows progressive unlockingThe device under tension in reverse mode with a simple carabiner and without effort. Protects the rope and facilitates rope and rappelling maneuvers: It does not curl the strings in any of the modes used. Separate the strings when belaying and rappelling with two strings. Intuitive use: Aluminum locking ring for easy to identify reverse mode. cable to limit the movement in belay mode and the risk of loss of the device. diagrams for the belay and reverse modes engraved on the apparatus. Use with a symmetrically locking carabiner (am'd or william) for more efficiency.