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.