542A

0.1UF 200V potted plastic film capacitors - Used in Bell System station apparatus, specifically within telephone subsets and ringer circuits - VINTAGE 1959 - In the context of Western Electric equipment, the 542A was often used for:
Filter/Coupling: Managing audio signals within telephone circuits.
Noise Suppression: Helping to maintain clear communication by filtering out unwanted electrical interference.
Station Apparatus: Supporting the internal network boards of telephone sets or subsets