Info: Various Replacement Parts for Ball Chair
Replacement or supplementary parts are available for Aviva's Ball Chair (sold separately), including the ball itself, various types of wheels, and height extenders. Please see notes below for details.
For Aviva's Ball Chair (shown in main photo; store code 11883) can help take pressure off the spine, release muscle tension, correct posture, improve balance and strengthen the torso. This ball, which can be inflated up to ~52 cm (10.4 inches) in diameter (it fills using a needle valve on a pump (not included), and comes with a long stopper).
Apart from use with these chairs, these balls are also suitable as exercise/yoga balls.
Various Ball Chair Wheel Sets
The wheels pictured on the top of this nearby photo are standard, free-rolling wheels (store code 11294). The wheels below it are manually locking (store code 17519): depending on how the small tab is positioned, it either enables sliding/movement while seated, or it locks the wheels in place to keep the chair stationary (two locked wheels suffice to hold the chair in place).
The auto-locking wheels (not pictured; store code 11246) are the ones normally sold with the chair; they are weight-activated, to prevent rolling when you are seated, and the locks release when you get up, so the chair can be repositioned.
Ball Chair Height Extension Adjusters
Set of 4 chair leg height extenders recommended for taller users or those sitting at a slightly higher desk surface. These 5 cm extensions (pictured right; store code 10459) are for use with the Aviva Ball Chair and also fit the BalanceBall Chair from Gaiam.