An essential item for Breast Feeding Mothers, the ultra soft Philips Avent Breast Shells are worn inside your bra to protect your nipples from chafing and to collect leaking breast milk. Includes 2 x Ventilated Breast Shells 2 x Non-Ventilated Breast Shells 2 x Ultra-Soft Backing Cushions Protects Sore Nipples The Ventilated Shells protect sore or cracked nipples to help them heal more quickly. Their gentle pressure helps relieve engorgement. The holes allow air to circulate. Collect Excess Breast Milk Breast milk collection shells (no holes) collects excess breast milk when feeding or using a breast pump.