Our Studio Pro 500Kg Swiss Ball with Pump - 55cm is rated at a massive 500Kg and is one of the toughest balls available. These balls have been extensively tested by SGS Laboratories for burst-resistance and static loading. Perfect for weight training, Fit Ball workouts, Yoga, Pilates or physiotherapy. The ball comes boxed complete with blaster pump. Size: 55cm ball To suit: those under 5`6 Colour: Purple Weight: 1300g Safety Tests: SGS Labs tested as burst-resistant at 750Kg load. Rated as suitable for 500Kg load SGS Labs tested with a static load of over 1.75 tons without failure.