Neil, one pin has the rubber sleeve and one is a pin with a flat machined along it`s full length, both sides will have one of each. The one with the flat does not have a sleeve and is just a straight pin,the one with the sleeve is machined down to take the sleeve but but nit has a retaining lip at the end. I don`t think you can buy the sleeve separate. Caution don`t take too much material out of the pin hole when you clean it up as if the pin is loose you will end up with a rattly caliper and this will cause premature pad wear and possible caliper damage. hope this helps