The spectra and spots of all the maser transitions detected in the W51d2 subregion. The maser emissions are shown with colorful lines in the spectra of the H₂O and NH₃ (9,6) transitions, and marked with gray bars in the spectra of the NH₃ (7,5) and (6,3) transitions. The gray contours in maps of maser spots show the 1.3 mm continuum, of which the start, step, and end levels are the same as that in Figure 2.