BRAND NEW Aftermarket 20mm complete front brake master cylinder, fits all K100 4 valve and K1100 models and also all R850 and R1100 models except the R1100S. Fits ABS and non-ABS models. This is an anodized version, complete with piston installed, ready to bolt up. Now includes the rubber dust boot at no additional cost! BMW sells their new master cylinder for $529, save big here!!