These exercise balls are used to improve flexibility, coordination and balance, also to strengthen and tone abdominals, trunk muscles, arms and legs. Constructed of durable brightly coloured PVC with slip-resistant ribbed surface. These inflatable vinyl balls provide excellent therapy for perceptual motor training activity, especially for children with abnormal reflex patterns or for general exercises and group activities. Seamless construction withstands rugged use by active children and adults. Distance from shoulder to finger tip equals diameter of ball required.