Gio Pillow Donut Pillow Baby Pillow A breathable mesh cover and memory foam donut pillow. Size: Approximately 21cm x Approximately 31cm Likely the S size. - Type: Donut Pillow - Material: Memory Foam - Cover: Mesh Material - Design: Triangular Pattern From the website: S Size Approximately 200 x 300 x 40mm (for 0-6 months) Suitable size: Head circumference approximately under 40cm M Size (separate page) Approximately 230 x 330 x 60mm (for 6-24 months) Suitable size: Head circumference approximately 41cm or more L Size (Kids) Approximately 280 x 400 x 80mm (for approximately 24 months - 8 years old) No central hole Thank you for viewing. Scientifically designed baby pillow usable from newborns 【 Gio Pillow 】 A baby's head is very soft, and even slight pressure during sleep can unknowingly distort the shape of the head. That's why it's important to take good care of them from the newborn stage. Gio Pillow is designed with a depression in the center of the pillow to fit the baby's head circumference, eliminating the need for adjustments and gently enveloping the baby's soft head. This leads to a natural and balanced head shape. Furthermore, the 3D layered structure disperses the pressure on the back of the head, and the donut-shaped structure, which supports the weight as a whole, firmly prevents head deformation. GioPillow Flat Head Prevention Baby Pillow