Abstract: A system has a connection element for the electrical connection of a first electrical assembly and a second electrical assembly. One of the assemblies is disposed in an explosion protected space and the connection element is arranged in an opening to the explosion protected space and closes the opening. The connection element has a cylindrical sleeve releasably arrangeable in a holder of the opening. The connection element has at least one printed circuit board in the cylindrical sleeve, with the printed circuit board having a plurality of conductor tracks for the electrical connection of the first electrical assembly and the second electrical assembly, with the connection element having a cast part. The printed circuit board is fixed and sealed in the cylindrical sleeve by means of the cast part, and with respective ends of the printed circuit board having the respective conductor tracks projecting from the cast part.