Many users desire a universal wrench with the widest possible range of applications. It should be a single tool for multiple metric and imperial sizes. It should automatically adjust to different screw sizes, grip securely, avoid damage, and allow for high work speed. The continuously and parallel-guided jaws replace several individual sizes of open-end wrenches. The required size automatically adjusts when applied to the hex nut or bolt. The integrated lever mechanism securely clamps the hex screw or nut between the jaws, significantly reducing the risk of slipping and damage. The ratchet function enables quick and continuous screwing without having to lift the tool. By utilizing corner width prisms, a return angle of only 30° can be achieved. The single-arm design combined with the ratchet function and corner width prism allows for work in tight spaces. The adjustable Joker 6004 is the universal wrench. Self-adjusting. Gripping. Ratcheting.