InnFocus, Inc.

The developmental breakthrough was found in a family of biostable polymers developed a decade earlier at the University of Akron and subsequently licensed by InnFocus, whose experts then reformulated and purified it, rendering the material medical grade. The foundation of the remarkable biostability of SIBS is the base polymer, comprised of a central polyisobutylene block capped on both ends with polystyrene. This triblock polymer has no sites for degradation and no risk of forming brittle double bonds that could affect its longevity in the body when flexed.1,2

From the manufacturer's own website. Source