Petzl's Grigri has become a standard in the climbing community over the past decade. Climbing gyms now test on them, and a lot of elite climbers rely on their belayers to use the Grigri for its dependable assisted braking and slack-feeding. Petzl simply nailed the balance between assisted braking and slack-feeding with this contemporary model of the Grigri Belay Device. For this newest model, Petzl expanded the rope diameter by optimizing the use specifically for ropes ranging from 8. 5 to 11mm. After doing all the research, there really isn't a larger rope diameter ideal for ropes as skinny nor as thick as the modern Grigri. Compared to the Grigri+, this specific model is ideal for experienced belayers and advanced climbers.