Battery Wall Set
Pattern No. B325
Comprises Wall Instrument fitted with Automatic Switch-hook, Induction Coil, Bell, and Push Button; Breastplate Transmitter (Granular Carbon) complete with Cords, Elastic Web, and Battery Switch; also a Metal-band Headgear Receiver, and Cup-hook for suspending same.
This set is intended for use by persons requiring the free use of their hands for typewriting,
shorthand, etc. It is, for the purpose for which it has been devised, by far the most convenient Set upon the market.
If fitted with a Double Headgear Receiver (Pattern No. B70), in place of a single one (Pattern No. B65) as above.