What is this part?

[Kenny Phillips]

I actually have two, labeled 'R' and 'L'.
Steering springs for something or other?
(I inherited a trailer full of misc. parts from a shop whose owner died.)

 

[Larry Korona]

Brake master cylinder

 

[flyingron]

Google matches it up with this listing:

https://www.ebay.com/itm/225346135178