Our standard mass loss reference model of a stripped star in shaded blue area together with three Kurucz models corresponding to main sequence companion stars of spectral types O9V, B1V, and B8V (approximate masses 20, 11, and 3 M_⊙, parameters given in Table 3). The available wavelength bands from the ground, from space, and in the extreme UV are shaded in white and gray backgrounds. Above the plot we show the wavelength ranges probed by various telescopes; colors show active telescopes and gray shows deactivated telescopes. In the extreme UV where the bulk of the emission from the stripped star is dominant, no telescope is currently available. In the optical there are many available instruments, but in this region even low-mass companions could clearly dominate the emission of the binary star. With lower mass companions some of the strong emission lines of the stripped star could pierce through the spectrum of the companion, but with higher mass companions it would be very difficult to see a stripped companion from optical spectral analysis.