This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
TrollyHeadworks. Electric bus trolly mechanism San Francisco Muni pole support springs and motion dampers Image by User Leonard org TrollyHeadworks org LeonardG Massspringdampers Trolleybuses in San Francisco Trolley poles
Page 2023 Free-images.com. All images are Public Domain