Upgrade your RC model with the OS Inner Head for 21VZ-B V-Spec. Designed for OS brand engines, this high-quality inner head is compatible with the 21VZ-B V-Spec engine and will improve its performance. Made from durable materials, the inner head is a perfect replacement part for worn out or damaged components. Take your RC model to the next level with the OS Inner Head for 21VZ-B V-Spec.