Our exercise ball is made from durable anti-burst PVC, there’s no danger of them bursting if they get punctured. Instead, they’ll slowly deflate to ensure your safety. In addition, the gym balls are covered in anti-slip lines to provide optimum grip on smooth flooring and prevent them sliding around. Gym balls are a versatile fitness aid which can be easily incorporated into a wide range of exercises, including crunches, bridges, dumbbell workouts, yoga, Pilates, and more. As well as targeting the usual muscles, adding instability to exercises has the added benefit of giving your core stabiliser muscles a serious workout. As an added bonus, each gym ball includes a pump to easily inflate to the correct capacity. QTY 300 and over are based on shipping by sea.