Pattern No. B640
Comprises Hand Combination Transmitter and Receiver, Cord, Automatic Cradle - switch, Induction Coil, Lightning Arrester, Magneto Generator, Bell, Line Selector, and Wall Rosette and Cord.
The same general remarks apply as in the case of Patterns Nos. B625 and B630, and, further, the Line Selectors of both patterns (Nos. B635 and B640) are fitted with a mechanical click which reduces the risk of making contact with two stations at once.
5, 10, 15, 20, 25 & 30 line models.