Astar Memory Foam Head Rest Car Pillow M139 Temperature-sensitive memory foam interacts with body heat to gently mold to ones shape and provides customized comfort This head rest car pillow is ergonomically designed for better neck and cervical support This head rest car pillow is particularly good for use when driving and can also be used at home, in the office or when traveling The head rest car pillow's height-adjustable strap fits most chairs.