There are several components that make up the caster assembly on your Invacare Pronto M91. If you find the tolerance ring is the culprit of a spasmodic excursion, why buy more than what you need?
This is the tolerance ring made just for the caster assembly of the Invacare Pronto M91. Now with a quick dissemble of the caster, and swap of the tolerance ring, you can smooth and straighten your ride.
⚠ WARNING California Residents:
Proposition 65 Warning