These new membrane seals replace punctured or torn seals on throttle slides fitted to Keihin CV Carburetors, Fits all stock Keihin CV carburetors on 1988 to present Sportsters, 1990–1999 Big Twins & 1999 to 2006 Twin Cam models. Why buy a complete slide assembly when you can now replace the seal only in a cost effective manner, these seals are not available or sold separately from the OEM.