Manufacturer: The British Thomson-Houston Co. Ltd.
Lamp Power: 0.5 Watts
Lamp Current: 2 Milliamps
Lamp Voltage: 100-260 Volts (Requires External Resistor)
Cap: B22d/22 (Brass)
Bulb Finish: Clear
Bulb Type: S-28
Overall Length: 56 ± 3 mm
Light Centre Length: Not Published
Electrodes: Split Ring
Atmosphere: 1.5% Argon in Neon
Luminous Flux: Not Published
Luminous Efficacy: Not Published
Colour Temperature & CRI: Not Published
Chromaticity Co-ordinates: Not Published
Rated Life: Not Published
Factory: Ponders End England
Date of Manufacture: September 1950
Original / Present Value: Unknown
References: 1) BTH Mazda Lamp Catalogue, 1950.