V-Grip Toothed Jaw
The working part is a V-shaped jaw lined with teeth, made from stainless steel and zinc. Push a lid up into the V until it wedges, and the teeth bite into the rim so it cannot spin; then turn the jar counterclockwise and the lid stays put and unscrews. The V shape is what lets one tool cover every size. Small caps, such as a water bottle or a medicine bottle, wedge near the point, while large jars sit toward the open end, and one owner uses it every day for both the small top of a water bottle and the wide lid of a spaghetti sauce jar. It copes with factory-sealed and vacuum-sealed lids as well as ones that are simply stuck, because the grip comes from the teeth rather than from friction. The trade-off of a toothed grip is marks. The teeth can score painted or thin lids, and one owner found that a lid with a slightly protruding edge was left with a sharp burr after opening, which only happened once in years of use. It is worth checking a lid's edge before handing a jar to a child, and wiping away any metal flakes from a lid you intend to reuse.
