Classic version with 139 ventilation holes Age: 0 – 6 years Different heights can meet the developmental needs of babies at different ages Low curve 3 cm is for 1-3 years old babies and high curve 5 cm is for 3 to 6 years old babies Ergonomic curve design is for neck and spine protection, which perfectly fit the baby’s curve With removable and washable Pillow case which is made of cotton Don't wash the memory foam pillow and don't expose to the sun, so as not to damage the structure and affect the use Pillow filler: slow rebound memory foam Pillow outer surface material: 100% polyester fiber Size: 50 cm x 30 cm The pillow will gradually turn yellow after contact which is normal characteristic of material, not a quality problem and doesn't affect the product use