This is a lid/gasket for a milking machine. The entrances hook up to the tubing for the milking machine. Typically they come in 3 entrance sets, but 2 entrances is not unheard of. I've linked two pages, one with a 3 entrance on Amazon (you can also find more 2 entrances on there) and one to almost the exact same model you've got here but the website is in Russian - apologies on that. They are manufactured by several companies, and they come in a variety of sizes and models.

This is a lid/gasket for a milking machine. The entrances hook up to the tubing for the milking machine. Typically they come in 3 entrance sets, but 2 entrances is not unheard of. I've linked two pages, one with a 3 entrance on Amazon (you can also find more 2 entrances on there) and one to almost the exact same model you've got here but the website is in Russian - apologies on that. They are manufactured by several companies, and they come in a variety of sizes and models.

References:

https://sibagro24.com/p38786710-kryshka-prozrachnaya-dlya.html

https://www.amazon.com/Gallon-Milking-Machine-entrances-Melasty/dp/B07G6TK1LH