A locking device for releasable locking with a counter body, having a base body, which is connected together with an add-on element and a connection element, and actuation means. One or more slides are fastened to the actuation means, which exert a relative movement to the locking device, whereby the slides are able to be brought into contact with the locking means and these can be transferred into a counter geometry of the counter body. Here, the actuation means remain in their respective position due to the return springs of the locking means and of the tension resulting therefrom as well as of a frictional resistance between locking means and slides. An automatic securing device is provided as secondary securing, designed as a spring-loaded securing bolt for securing the position of the actuation means and prevents unintentional opening of the locking device.