ROLA MODEL 5B (CIRCA 1954)

The Rola model 5B was manufactured by Loudspeakers (N.Z.) Ltd in about 1954.

Specifications from an advertisement in Radio and Electronics, July 1954.  Found in many early mantle sets. 

Power Handling: 2½ Watts
Frequency Response 145Hz - 6.5kHz
Impedance 3.5Ω @ 400Hz