Belay device with assisted braking for 8.9 to 11 mm rope The GRIGRI 2 belay device with assisted braking is designed to facilitate belay maneuvers. The GRIGRI 2 works equally well for lead climbing and top roping. It may be used on all 8.9 to 11 mm dynamic single ropes (optimized for 9.4 mm to 10.3 mm ropes). Compact and lightweight, the GRIGRI 2 will accompany you for many years, on climbs all over the world. The GRIGRI 2's design allows for excellent descent control.