The German company POLYTOP has developed a special bottle cap that prevents children from opening the bottle and can measure automatically. It is most suitable for capping containers filled with potions or powders. There is a narrow slit on the bottle cap. After the bottle is reversed, the liquid or powder in the container flows out through the narrow slit. Once the prescribed dose is reached, the outflow automatically stops and the metering is accurate. In addition, BEAMAS has also developed a square bottle cap that can be matched with 125MM, 200MM and 250MM square polyethylene bottles, which can tightly seal the bottle mouth.