With the power bleeder , one person can easily and effectively bleed the brakes. The power bleeder uses pressurized brake fluid to force air and contamination out of your lines. You’ll get all the air out of your system the first time you bleed. No need to re-bleed. With the built-in hand pump, no air com-pressor is needed. Comes with threaded cap to screw onto Wilwood or Tilton master cylinder reservoir