Feature: 1. GET THE RIGHT FLARE SIZE: The flare size of the breast pump is important for breastfeeding. An improper flange size may reduce comfort and efficiency during pumping. This nipple ruler helps you quickly determine the appropriate nipple shield size for a more comfortable experience. 2. SOFT AND SAFE MATERIAL: The nipple ruler is made of high-quality silicone, non-toxic, odorless, lightweight, and flexible. Unlike rigid plastic with sharp edges, this ruler is soft, bendable, and gentle on the skin. 3. ACCURATE AND QUICK MEASUREMENTS: With clear scales along the edge and multiple measurement holes, the ruler allows for precise sizing. It includes 21 nipple measurement holes ranging from 10mm to 30mm, making it easy to read and use. 4. SIZE ADJUSTMENT: Depending on your nipple elasticity, you may need to choose a smaller size if your nipples are highly elastic or a larger size if they are less elastic. If discomfort occurs or milk output decreases, consider trying a different size. 5. PERFECT GIFT: A thoughtful and practical gift for new mothers to help them find the right fit and support a comfortable breastfeeding journey. Specification: Item Type: Flange Measurement Tool Rectangle Size: Approx. 18 x 10 x 0.3cm / 7.1 x 3.9 x 0.1in Round Size: Approx. 11.6 x 11.6 x 0.3cm / 4.6 x 4.6 x 0.1in Material: Silicone Package List: 2 x Silicone Measuring Stick