The REVO is the only automatically locking belay device which has a completely panic-proof locking mechanism. Product Description The REVO has no method of over-riding the locking mechanism, during belaying, or when lowering a climber. Bi-directional: the locking function works regardless of the rope direction. Intuitive belaying method, which requires no changes to standard belaying technique. No need for a specific locking karabiner. All of these USP&';s contribute to make the REVO the safest belay device available. Weight: 245g Rope Range: 8.5-11.0mm