Abstract: The opener/closure of the present disclosure relates to devices permitting the opening or closing of twist cap containers. It comprises a rectangular housing in which a pair of cap gripping jaws are slidably mounted for movement toward and away from each other, and in which the jaws are interconnected by a cable in a manner whereby movement of one jaw in one direction is effective to move the other jaw in the opposite direction, whereby when moved toward each other both cooperate to grip a container twist cap either for loosening or tightening the cap to open or close its container. A standard positions the container below the housing by a strap tightly holding it securely against rotation as the jaws grip the cap, and the housing is manually rotated to loosen or tighten the cap on the container.