- Belayer requires significantly less hand braking force to arrest a fall
- Lowering a heavier climber is much easier to control
- OHM is attached at the first bolt in the safety chain
- Should a lead climber fall at the first bolt, the OHM significantly reduces the risk of a possible ground fall
- Rope handling when belaying a lead climber not affected (no additional friction when paying out rope)
- Recommended weight difference (lead climber > belayer): 10–40 kg
- Minimum belayer weight: 40 kg
- For single ropes from 8.9–11.0 mm
If there is a significant difference in weight between lead climber and belayer this frequently causes problems. This applies in particular to climbing couples, where the woman is often significantly lighter than her partner.
In the event of a fall, a lighter belayer can be suddenly pulled off the ground and hurled against the wall. In addition, when a belayer is pulled high off the ground, this significantly increases the distance that the climber falls. If the climber is still near the ground, belayer and climber might collide. In the worst-case scenario, the climber might hit the ground.