Description of Petzl GRIGRI Self-braking Belay Device Device for belaying a leader or a second and for single rope descents. Features: Self-braking system: if the rope suddenly comes under tension (e.g. in a fall), the cam pivots to pinch the rope, thus helping the belayer stop the climber's fall. Usage is similar to that of conventional belay devices: Giving/taking slack is done by using both hands to slide the rope through the device, Falls are held by holding the free end of the rope, For lowering and rappelling, the rate of descent is controlled by the hand holding the free end of the rope (the rope is released with the handle). For ropes of diameters from 10 to 11 mm. 225 g.