The Mid-Sized D-Core is a medium sized cervical support pillow that helps relieve tension, headaches, and neck spasms by providing proper alignment of the neck. The cervical roll and D-shaped center gently cradle the head and neck for better sleep when on your back. For back sleeping, a firm cervical roll supports the neck while the D-shaped center gently cradles the headfor better sleep. For side sleeping, the raised side panels help keep the head level for proper alignment of the spine.In order to provide therapeutic benefits and help restore the natural curve of the neck, two firm cervical rolls provide different support options. Use the smaller neck roll if you are in the adjustment phase or if you prefer slightly less support. Use the larger neck roll for maximum support. It may take some time to adjust to this cervical pillow and immediate overuse may actually increase neck pain. For best results, slowly ease into orthopedic correction by alternating between this pillow and your current pillow. The Mid-Size D-Core Pillow fits loosely in a standard pillowcase. Pillow size: 23 x 15 (58cm x 38cm). Made in USA.