The cocoon nylon sythentic fill pillow all cocoon air core travel pillows feature inflatable air cores underneath a layer of premium synthetic or hydrophobic down fill and combine the comfort and support of superior pillows with minimum packing size a twist valve on all pillows allows you to customize your level of comfort and support instantly the new generation of air core pillows comes with zippers and exchangable air cores no more emergeny situations while traveling even if no extra ai