Frequency Calibration Wand

Cylindrical black-cased calibration wand or frequency standard tube, featuring a printed cream-coloured frequency scale ranging from 240 kHz to 440 kHz with fine tick marks and numbered intervals. The markings are printed in black, and the top bears the Telefunken brand name.
This accessory was used in conjunction with the Telefunken PE-484 or related receiver units to tune and verify frequency accuracy during signal calibration.