A lot of people don’t know what these little things are - including people in auto parts stores - so I thought I’d post a message about them. They replace the brake bleeder screws - they look just like the original equipment, only slightly longer. The extra length is to accommodate a ball valve inside the bleeder screw.
The ball valve closes the bleeder off unless there’s line pressure from the brake pedal being pressed. So you crack open a Speed Bleeder, then pump the brakes, and it automatically opens and closes the valve to bleed the fluid, rather than having to have someone there with a wrench. When you’re done, you close the speed bleeder like you do a normal bleeder screw, and leave it on the car. Takes a few minutes per side and makes the job a whole lot easier, and most important, doable by only one person.