I’m looking for D.O.T. air brake tubing. What does this mean?

Brotec air brake tubing is manufactured to several standards such as the European DIN74324 and the American standards J844 Type A and J1394 Type A. When D.O.T. is specified it relates to the American standards. The fittings are also specified D.O.T. which stands for the American Department of Transport. Brotec air brake tubing is manufactured to D.O.T. specifications.