STERLING TELEPHONE AND ELECTRIC Co. Ltd
STERLING "PRIMAX" SYSTEM OF AUTOMATIC INTERPHONES
ALL LOCAL BATTERIES ARE ENTIRELY DISPENSED WITH
No. U 410
Automatic Interphone, Wall Pattern (Radial Switch Type) Revolving Granular Carbon Transmitter, Induction Coil, Double Pole Watch Receiver, Call Bell, Automatic Switch Hook, "Perfecta" step-by-step Radial Line Selector, Automatic Cut-in and Cut-out Device, Ringing Key.
Metal parts are Nickel-plated and Woodwork is Solid Walnut.
Available in 5, 10, 15 or 20 lines. (Over 20 line models made to order)
Taken from the Sterling Catalogue No. 11 & 12
Last revised: April 28, 2021