The Diono Monterey 4 DXT 2-in-1 Booster Seat is designed with versatility in mind, offering low and high headrest options with adjustable side wings and an adjustable booster for your growing child. The headrest is lined with thick foam for more comfort and side impact protection. Plus, it contours to your little one and expands as your child grows, securing their head and shoulders up to 12 years old.