XPRT Fitness Exercise and Workout Ball, Yoga Ball Chair, Great for Fitness, Balance, and Stability Extra-Thick with Quick Pump (55/65/75 cm) - Walmart.com
RGGD&RGGL Exercise Ball Chair(55-75cm), Extra Thick Yoga Ball with Adjustable Resistance Bands, Stability Ring, Workout Guide,Anti-Burst Balance Ball for Workout and Fitness (Mint Green, 55cm) : Amazon.com.au: Sports, Fitness & Outdoors