Our BlackOut power brake conversion for the 1955-57 Belair consists of a 9″ Black Booster and Black POL or Wilwood master cylinder and Black Outadjustable proportioning valve. Performance Online introduced this in 2013 and received a huge response. This kit contains a powder coated booster, Black POL or Wilwood high performance master cylinder, black adjustable proportioning valve and black powder coated brackets to add a nice professional detailed look to your classic. Improves stopping distances and driver performance tremendously.