A nut cracker having a cup, a lever and a handle. A working solution containing a reactive carrier compound is hydrogenated with hydrogen in a microreactor and is subsequently auto-oxidized to produce hydrogen peroxide. Thus, a composite laminate is obtained. The second device determines a user account for the service, the user account being associated with the user identifier for the user. Whereby, suction can be conducted without being influenced by suction ends of other suction paths.