Original Number is the original manufacturer's part number, printed or stamped on an article. You can often see these figures on dampers or brake drums.
Where do I find my brake ID?
You’ll find your brake ID on the drawbar, brake anchor plate or on the axle. On trailers dating from 1994 onwards the brake ID is an EG or EU number. If you don’t find any brake ID you can use original type number.
Brake drums
When you identify brake drums you also need to know the total weight of the axle since different brake drums can have the same brake ID. The weight can often be found on the axle.
Below are examples of brake ID plates. The yellow arrows show the locations of the brake ID numbers and the blue arrows show the type numbers on the plates.