GPO/BT 21A Transmitter Unit
Genuine GPO 21A transmitter units. Good used working condition, with minor surface rubs to outside of the red casing as shown.
Ideal for use in 706 and 746 telephones and can easily be removed from red outer casing for use in Bakelite telephones.
PLESE NOTE: I ship single 21s uncased with the two back screws included, but removed so that it can be shipped as a 'Large Letter' - This dramatically reduces postage costs.