What is the brake bleeder screw look like?

The brake bleeder screw is typically a small metal fitting, often made of brass or steel, located on the brake caliper or wheel cylinder. It usually has a hexagonal shape, allowing for easy access with a wrench, and features a small hole at the top where brake fluid can escape during the bleeding process. The screw often has a rubber cap to protect it from dirt and moisture. Its primary function is to release air from the brake lines, ensuring proper brake system function.