Disc Brake Trailer Axles

https://www.zytrailerparts.com/products/disc-brake-trailer-axles/

A disk brake trailer axle allows you to stop quickly, even when the load is heavy. You can set these axles up with electric or hydraulic brakes, depending on your needs. They fit most 20- and 24-inch wheel sizes and come in 2 to 3-inch increments.