A wedge brake chamber is a type of air brake used on heavy vehicles such as trucks, buses, and trailers. It consists of a housing that contains a spring-loaded wedge that is activated by air pressure. When the brake is applied, the wedge is forced outward, pushing against a pair of brake shoes and causing them to press against the inside of the brake drum. This creates friction, which slows the vehicle down. The wedge brake chamber is a common type of brake system used on heavy vehicles because it is reliable, durable, and easy to maintain.