This is a center-applicator T-bar slide-rule dial pointer (part #105505-1). It features a 1 1/2-inch horizontal mounting bar with a 3/8-inch wide center applicator bracket that secures to the dial cord or guide track, extending a short 7/8-inch indicator tip. This style was designed for compact slide-rule dial scales and edge-lit glass assemblies found in tabletop radios and consoles manufactured by companies like Philco, Zenith, RCA Victor, General Electric, and Crosley.