This new hypoallergenic and water-resistant cover was designed in response to numerous customer requests for a liner that would protect the Boppy Pillow from wetness. It fits over the Boppy Pillow and under the Fashion Slipcover, similar to a mattress pad for a bed, providing added protection from spills and accidents. Limit your pillow washings with this handy cover. The Boppy Protective Cover fits all Boppy Infant Feeding and Support Pillows (sold separately).