Early brass radiator cap. I believe teens or early 1920’s Briscoe automobile. Good shape for age but does have some dings. See pictures. Feel free to ask questions. No reserve. 

Measures around 3-3/4 inches wide. Inside diameter is around 2-1/4 inches.

I am just starting to list a bunch of early automotive accessories from a great collection. Keep an eye on my upcoming auctions. All listings with the green background are no reserve auction and start at $0.99.