hi mate i just got mine from aprilia dealer its in the post i hope .ive looked at the after market ones ,1 looked like the standard slave and the other had 2 main seals instead of 1 which wont make **** of a difference as it will only be the rear seal that will be doing the work .and 2nd seal will make piston slower to return ..only good thing was they were anodised but the difference in price much more ,one company said theres had a bigger piston blah blah blah ,,, now you see why mines coming from aprilia save your money fit standard