The Bitty Bottoms seat cushions measure a mere 8" (20cm) across and are perfect for smaller bottoms. Each Bitty Bottom is molded to be a perfect fit and contains either small PVC balls or crunchy beans for a smooth or more sensory experience, respectively. Cushions are ideal for kids who need to wiggle, fidget and move! Use on the ground, in a chair, during mealtime, circle time and just about anytime! PVC Ball filled. Abilitations Integrations.