The Flexyfoot Replacement Foot - Black has been created to be a replacement for when the Flexyfoot rubber ferrules \"foot\" is worn or broken.It comes in one size and fits all Flexyfoot ferrules. It simply screws into any Flexyfoot collar, which is that par that is attached to the walking aid. For greater shock absorbency if full weight bearing is needed or for the more active user, all replacement feet come with two O rings that can be fitted to the foot. The Flexyfoot Replacement Foot comes in both grey and black tread from this section of the website.