As the first bi-directional assisted-braking belay device, the Revo promises that a climber will never misthread the rope, which eliminates one of the biggest dangers in assisted-braking devices. The Revo opens easily, and the rope can be threaded with the climber’s end coming out of either side. Testers found that the device never locked up while pulling out slack, meaning no short-roping, even on long and fast clips. Despite this, the device locked up quickly when climbers, both light and..." go to full review