Left: the log-periodic spiral arm fits. The shaded area shows the estimated Perseus arm widths. Right: plan view of the Milky Way. In both plots, the dashed lines are the spiral arm fits for the Outer (red), Perseus (black), Local (cyan), Sagittarian–Carina (magenta), and Scutum–Centaurus (blue) arms, from Table 2 of M. J. Reid et al. (2019). The solid black line shows the Perseus arm fit from Figure 1 of M. J. Reid et al. (2019), while the other solid lines show the new models from this work (yellow for single-segment, blue for two-segment Perseus arm), the Sagittarius arm (magenta; S. B. Bian et al. 2024), and X1 bar orbitals (lime; J. Kumar et al. 2025). The green square shows the location of the Galactic center [0, 0], the Sun is shown with a red star at [0, 8.15], and new maser parallaxes from this work are highlighted with red circles.