Many users desire a universal screw tool with the widest possible range of applications. It should be a single tool for multiple metric and imperial dimensions. It should automatically adjust to different screw sizes, grip securely, avoid damage, and enable high working speeds. The continuously adjustable and parallel-guided jaws replace several individual sizes of open-end wrenches. The required size adjusts automatically when applied to the hex nut or screw. 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 allows for quick and continuous screwing without having to reposition. 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, enables work in tight spaces. The adjustable Joker 6004 is the universal screw tool. Self-adjusting. Gripping. Ratcheting.