Many users desire a universal wrench with a wide range of applications. It should be a single tool for multiple metric and imperial sizes. It needs to automatically adjust to different screw sizes, grip securely, avoid damage, and allow for high working speed. The continuously adjustable and parallel-guided jaws replace several individual sizes of open-end wrenches. The required size automatically adjusts 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 enables quick and continuous screwing without needing to reposition. By utilizing corner width prisms, a return swing 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.