Keep young children secure and comfortable with the Carlisle 911403 Stackable Booster Seat. This booster seat is made of durable polypropylene that has an added antimicrobial agent to prevent the growth of odor-causing bacteria. Integrated straps go around the child's waist to keep them secure, and a built-in cup holder ensures sippy cups are within reach. The booster seat is even stackable to save space.