This soft silicone nipple ruler is designed for breastfeeding measurement, providing a safe and non-toxic way to determine the right breast pump size. Made of soft and comfortable silicone, it can be bent and folded without worrying about scratching the skin. The ruler has 21 circle sizes and is easy to use, simply align it with the edge of the nipple side and observe the size in the mirror. It is a useful tool for new mothers, helping them to quickly determine the right breast pump size and making breastfeeding easier and more comfortable.