The "Plus Test" is a rigorous Swedish safety test for child car seats. This test is considered one of the most demanding in the world in terms of collision safety, focusing especially on the forces exerted on the child's neck in the event of an accident. Unlike standard crash tests, which may only assess frontal impact, the Plus Test also evaluates the impact of more severe collisions and the seat's ability to limit the forward movement of the child's head—a critical factor in preventing serious or fatal neck injuries in young children. The tests are conducted exclusively rear-facing.