What do you call a plastic contraption placed inside tip of liquor bottles to regulate its flow contents?

Pourers are designed to:

* Control the flow of liquid: They prevent the liquor from pouring out too quickly, creating a smoother and more controlled pouring experience.

* Prevent drips and spills: They usually have a lip or a spout that helps direct the liquid into your glass.

* Enhance aesthetics: Some pourers are also designed to be decorative and add to the overall presentation of the bottle.