Grigri
A Grigri is a securing device for rock climbing. Unlike many other securing devices, a Grigri is half-automatic. It works like a seat belt in a car. The rope can be slowly pulled through, but if there is lot of weight on the rope the Grigri locks the rope. "Grigri" is a trademark of the company Petzl, but because it was the first half-automatic securing device, many people call devices of other companies also Grigri.