Here, within the Scale-Symmetric Theory (SST), the correct interpretation of the Kaluza-Klein theory (KK theory) is presented. In SST, the charges are the spinning tori whereas in KK theory they are the masses moving along circle-like fifth dimension. The most incredible fact is that when we abandon the international system of units then the product of the mass of the torus/charge of proton in SST and speed of light (i.e. the fifth momentum) is very close to the value of the electric charge of proton or electron i.e. there is possible the interpretation that electric charge is the motion of mass in the fifth dimension. Moreover, the fifth momentums for the quantum entanglement and electric charge of proton have the same values but physical meanings and densities of adequate radion fields are different. Spinning torus collapses to spinning circle. In reality, the fifth dimension is the additional degree of freedom which follows from the real structure of charges. The fifth-dimension simplification causes that we lose information about internal structure of charges i.e. the KK theory is an effective theory of the SST. Radions are the components of the fifth dimensions. The SST shows that gravitational radions are superluminal whereas electromagnetic radions are luminal i.e. we cannot unify the two different radion fields within the same methods and it concerns the generalizations of the KK theory also (for example, the Yang-Mills theories). The SST shows that the cylinder condition in the KK theory follows from the fact that there are the spinning tori/charges and spinning loops. The luminal electromagnetic radion field leads to photons but the superluminal gravitational radion field does not lead to gravitons and gravitational waves. Emission of gravitational energy, i.e. a decrease in inertial-mass density of the superluminal non-gravitating Higgs field, is due to increase in gravitational-mass density of a system or due to emission of gravitational mass which carries non-gravitating gravitational field.