We claim the ornamental design for a showerhead and arm, as shown and described.
FIG. 1 is a left elevation view of a showerhead and arm.
FIG. 2 is an upper-right-front perspective view of the showerhead and arm.
FIG. 3 is a bottom plan view of the showerhead and arm.
FIG. 4 is a top view of the showerhead and arm.
FIG. 5 is a front elevation view of the showerhead and arm in the neutral position.
FIG. 6 is a rear elevation view of the showerhead and arm.
FIG. 7 is a lower-left-front perspective view of the showerhead and arm.
FIG. 8 is a left elevation view of the showerhead and arm with the showerhead tilted outwardly; and,
FIG. 9 is an upper-right-front perspective view of the showerhead and arm with the showerhead tilted outwardly.
Some broken lines shown in the FIGURES depict environmental structure. Other broken lines shown in the FIGURES depict alternative surfaces of portions of the showerhead and arm. However, no broken line shown in the FIGURES forms any part of the design claimed in the instant Application.