The Hammer by Petzl is for use with the Petzl Quark and Ergo ice axes. This ice axe hammer features a low profile trapezoidal shape that is great for wedging in cracks when climbing, and the angle of the contact surface coordinates perfectly with the curvature of the Quark's shaft. Don't stick your tongue to a cold metal surface outdoors, it may get stuck there. If this happens, simply cup your hands over the area and blow warm breath onto the metal until you can safely remove your tongue. I've heard that works.