Dr. Brown's SoftShape Silicone Shield is made of 100% silicone for a comfortable, flexible pumping experience no matter your breast shape. The soft silicone flange is gentle against skin and conforms to your breast for a better seal, making pumping more comfortable and efficient. The one-piece design is simple to attach and remove from breast pumps. The SoftShape Silicone Shield comes in three sizes: A (21 mm), B (25 mm), and C (30 mm) to find your best fit. Use with Dr. Brown's Manual Breast Pump or Customflow Double Electric Breast Pump. Dishwasher safe (top rack) and sterilizer safe. BPA free.