This is a slide-rule base-mounted dial pointer (part #104255-1). It features a 1" x 3/8" rectangular drive-mounting base designed to attach directly to a tuning dial cord, slider track, or drive cable, extending a straight 2-inch indicator needle across slide-rule glass dial scales. This style was commonly used in tabletop radios, compact receivers, and consoles manufactured by companies like Philco, Zenith, RCA Victor, General Electric, and Crosley.