24 500 1500 2500 3500 m GLYPH<LParen1> GeV GLYPH<RParen1> 100 FIG. 3: Graphical solutions of the eigenvalue equation (87) for the left charged sector. The intersections corresponding to the first and second KK excitations can be clearly seen. On the top right panel, the magnification of the low mass region showing the intersection corresponding to the zero mode, W. The neutral sector has a more complicated eigenvalue equation (48). However, it can be easily checked that, as soon as m ≫ m$_{Z}$ , the right-hand side of the equation is negligible so that it can be approximated: ( ˜ g 2 g 2 $_{5}$m$_{N n}$ sin( πRm$_{N n}$ ) + ( m 2 N n − ˜ g $^{2}$˜ v 2 4 ) cos( πRm$_{N n}$ ) ) · ˜ g ′$_{2}$ g 2 $_{5}$m$_{N n}$ sin( πRm$_{N n}$ ) + ( m 2 N n − ˜ g $^{′$_{2}$}$˜ v 2 4 ) cos( πRm$_{N n}$ = 0 . (88) The eigenvalue equation can then be approximately factorized into two independent ones; the first one is identical to eq. (87), the second one is similar with the replacement g → g ′ . The tower of the neutral eigenstates is then composed by two sub-towers, one of which almost identical to the one of the left sector. In Table I, we show the lightest part of the spectrum in an explicit example corresponding to a particular choice of the parameters. Let us now check the model against EW precision tests. In Fig. 4, we show the allowed region at 95% C.L. in parameter space ( M$_{1}$, ¯ g$_{5}$ ), based on the new physics contribution to the ϵ parameters. Here M$_{1}$ ≡ m$_{R}$$_{1}$ = 1 / 2 R is the mass of the lightest KK excitation, that is