Philips Avent Nipple Protector Standard SCF156/01 is made of ultra fine, soft, odourless, taste-free silicone that protects sore or cracked nipple during breast feeding. It contains 2 standard nipple shields, 21 mm diameter.Philips Avent Nipple Protectors are only designed for use when you have sore or cracked nipples and should be used with health professional advice.