How would you mold this?

Hi,

Im studying a piece that usually comes as a lid gasket on candles and other glass-ware with lids:

https://preview.redd.it/czze6xqcg3yf1.png?width=512&format=png&auto=webp&s=5d4f4213b8255579a694164e44fbf26969755c1e

It's basically a C-shape revolved, however as I am looking at the piece I dont see any clear "ejector pin marks" or "gate marks". I do see something that could be flash around certain edges but I am wondering if anyone has any idea on how these parts are molded: