JOES Brake Bleeder Bottle contains the mess of bleeding brakes by capturing the fluid in a 16oz. bottle. It comes with a magnetic adapter that attaches directly to your brake disc to make brake bleeding a one-man job. The one-way check valve is easy to use, just attach the bottle, open the bleed screw and pump the brakes. Each pump releases fluid out of the system and seals tight when you release the pedal. It works for the majority of brake systems without the need for an adapter.