Bleeding the brakes or changing the brake fluid is completed in a matter of seconds, even on your own: First replace the original bleeder screw on the brake caliper with this new bleeder screw equipped with a check valve. When changing the brake fluid or bleeding the system, simply release the screw on the check valve by a half turn and pump the brake fluid through the system with the brake lever. The valve prevents air from forcing its way back into the system on releasing the brake lever. Supplied with an anodized dust cap.