‎RBX

Make sure this fits by entering your model number.
Perfect for even the most rigorous and sustained workout, the RBX 55cm inflatable fitness ball provides a full-body workout for all fitness levels — from beginner to the most advanced.
A versatile workout tool, the fitness ball promotes stability and balance to strengthen and tone your abs, thighs, and lower back — improving your core strength, posture, coordination, and flexibility.