A "barb stem" or "espiga para mangueira" typically refers to a hose stem or hose barb, which is a component used for connecting hoses to various devices or systems. It has a barbed or serrated end that is designed to be inserted into the inside of a flexible hose, creating a secure and leak-resistant connection. The opposite end of the barb stem often includes threads or other connectors to attach it to a hose adapter, valve, or other equipment. Barb stems are commonly used in applications where a reliable and tight connection between hoses and other components is essential, such as in plumbing, irrigation, and fluid transport systems.