Connecting system for the fixed but releasable connection of individual segments (21, 22, 23) to form assembled units, with • a first connecting element which is arrangeable in a recessed and fixed manner in a recess of a first individual segment, and with • a second connecting element which is arrangeable in a recessed and fixed manner in an opening in a second individual segment, and with • a connecting member which is likewise configured for engaging in said recess and engaging in said opening and is designed for magnetic interaction with the first connecting element and with the second connecting element such that the connecting member undergoes a magnetic operative connection with the first and the second connecting element (16, 18), said magnetic operative connection resulting in a mutual attraction between the respective connecting element (16, 18) and the connecting member; wherein • the connecting elements (16, 18) or the connecting member or at least a part of the connecting member are/is designed as a magnetic element (30, 30', 30") and the other connecting element (16, 18) or connecting member or part of the connecting member interacting with said magnetic element is either likewise a magnetic element (30, 30', 30") or a magnetizable element, characterized in that • the connecting member has an intermediate piece between its magnetic or magnetizable end sides, • wherein the magnetic or magnetizable end sides are spaced apart from each other by a distance having a variable length, and • the intermediate piece is designed in such a manner that it permits an adjustment of the variable distance A between a minimum length and a maximum length, wherein the maximum length is up to 15%, better up to 50%, longer than the minimum length. • a first connecting element which is arrangeable in a recessed and fixed manner in a recess of a first individual segment, and with • a second connecting element which is arrangeable in a recessed and fixed manner in an opening in a second individual segment, and with • a connecting member which is likewise configured for engaging in said recess and engaging in said opening and is designed for magnetic interaction with the first connecting element and with the second connecting element such that the connecting member undergoes a magnetic operative connection with the first and the second connecting element (16, 18), said magnetic operative connection resulting in a mutual attraction between the respective connecting element (16, 18) and the connecting member; wherein • the connecting elements (16, 18) or the connecting member or at least a part of the connecting member are/is designed as a magnetic element (30, 30', 30") and the other connecting element (16, 18) or connecting member or part of the connecting member interacting with said magnetic element is either likewise a magnetic element (30, 30', 30") or a magnetizable element, • the connecting member has an intermediate piece between its magnetic or magnetizable end sides, • wherein the magnetic or magnetizable end sides are spaced apart from each other by a distance having a variable length, and • the intermediate piece is designed in such a manner that it permits an adjustment of the variable distance A between a minimum length and a maximum length, wherein the maximum length is up to 15%, better up to 50%, longer than the minimum length.