A switch core is set forth that comprises a plurality of duplex switches that are interconnected with a interconnection fabric to implement, for example, strictly non-blocking operation of the switch core for reciprocal traffic. The device comprises a storage holder for accommodating the pack of ring-shaped labels. In playback, the number of start parts recorded in a recording unit on the storage device is detected to identify the recording units to be reproduced. The first window and second window may be mechanically converted into an open position to cause the powder to mix with the water to create a solution that may be consumed by a user. The invention is characterized in that the transmitter unit comprises at least a removable wall providing access to the inside of a chamber with greater dimensions than those of the receiver unit.