Abstract: The invention relates to climbing chocks such as would be used by mountain climbers. Hitherto simple wedge shapes have been extensively used, the climber carrying a wide variety of sizes to fit into the various cracks in the rock surface. While the sizes have varied the taper angles have tended to be constant and while this is perfectly adequate in an instance where the taper of a crack is substantially the same as the taper on the chock, this does not always follow and particularly in irregularly shaped cracks contact is frequently reduced to two-point contact between the wall of the crack and the chock. The object of the invention is to improve the effectiveness of a climbing chock in irregularly shaped cracks while maintaining a high degree of effectiveness in a smooth tapered crack. This objective is met in a climbing chock having a generally wedge shaped body (1) two opposite side faces (6, 7) of which are respectively of concave and convex configuration.