Memory Foam Pillow - Material originally developed by NASA. There is a GEL layer on top of memory foam and makes the pillow cool to use in summer time and the other side good to use in winter. Excellent pressure-relieving property reduce pressure points on the neck and head, which can alleviate discomfort caused by poor sleeping posture. These pillows also often feature breathing ability enhancements, such as open-cell structures or ventilation channels, to prevent overheating and ensure a cool sleeping experience.