A scientist from the Ostfalia University of Applied Sciences has developed a multifunctional, self-locking fastener, which can be produced cost-effectively using plastic injection moulding and 3D printing. The hook-like component does not contain any additional components such as screws, nuts, axles, sapwood and springs. The connecting hook combines features of a rigging plate and a hook in one compact component. If two geometrically identical hooks are placed on top of each other by 180° around a longitudinal axis, the so-called hook connection unit is formed. This can be used in combination with a traction device (e.g. leash, rope and chain) for hanging and/or fastening of objects. Under load, a secure connection is established by surface pressing, which results in the self-locking functionality/mechanism. Fig. 1 shows some possible applications of the self-locking hooks according to the patent application. However, it is also quite possible that the hook eyelets are used to accommodate a carabiner or any other hook, an eyelet or an object that is to be held in place by the hook connection unit and by the traction device attached to the sling eyelets.