Edelrid Ohm, oasis brake-assis

Features
Ohm attaches at the first bolt in the safety chain; in the event of a fall, the rope is pulled into the device's braking unit and the fall is progressively arrested
With Ohm, belay normally with your preferred belay device; Ohm is not a replacement for a belay device
The Ohm makes it easier for a belayer to hold a fall and limits how high he or she is pulled off the ground; this can help reduce the distance a lead climber falls
Lowering a heavier climber is also easier to control
Ohm does not increase friction for the lead climber, nor does it negatively affect paying out the rope
For single ropes with diameters of 8.9 to 11mm
Recommended weight difference (lead climber > belayer): 25&38211;85 lbs.; minimum belayer weight 85 lbs.